The first information concerning the cytogenetic efficiency of thermal neutrons in lentil are presented in this paper. The range of cytologically effective dosages of thermal neutrons in lentil was determined. This determination enables us to compare the efficiency with the mutagenic effect of thermal neutrons and with their effect on the growth and development of plants of M₁ generation. These effects were already evaluated in previous communications.
Thermal neutron irradiation significantly affected all the characters studied. A linear dependence of the effect on the dose of the neutron radiation was found for most of the analyzed characters. From a sample of scored cells, whose nuclei were in the anaphase or early telophase, 9.0 to 72.0% of them had chromosomal bridges and fragments after irradiation with dosages from 3.3×10¹¹ n cm^-2 to 4.5×10¹² n cm^-2. The highest number of rearrangements per one cell reached 2.16 after irradiation with 4.25×10¹² n cm^-2 while the lowest dosage used, 3.3×10¹¹ n cm^-2, induced 0.17 of chromosomal rearrangements per one cell. Irradiation with thermal neutrons is capable of inducing a large number of very complicated chromosome rearragements.

In barley embryos, treated with N-methyl (¹⁴C)-N-nitrosourea, the alkylation of nucleic acids was much higher than that of proteins and lipids. At a concentration inhibiting the growth of M₁ seedlings to 50%, 0.27% of DNA-guanine was methylated to N-7-methylguanine. In barley DNA, alkylatedin vitro, the presence of 3-methyladenine and 0-6-methylguanine was chromatographically detected.

The interaction of GA and IAA in apical dominance was investigated in an experiment in which first of all an IAA paste was applied to the cut areas formed by the decapitation of epicotyl apices of pea seedlings, followed after one week by the application of a 0.25 % GA paste. The latter treatment was able to overcome the growth inhibition of cotylary buds induced by a 0.03 % IAA paste, but not that caused by 0.06 and 0.12 % IAA pastes.
The correlative function of a root in the renewal of the apical dominance can, to some extent, be directly simulated by exogenous gibberellin, as has been demonstrated in the experiment with decapitated pea seedlings deprived of one cotyledon, on which the growing axillary of the amputated cotyledon was decapitated. In this case the axillary of the remaining cotyledon grows in the plants where the root has been left, but in those deprived of the root, there appears a serial of the amputated cotyledon (Dostál, Biol. Plant. 9 : 330, 1967). When GA was supplied to the plants treated in this way, the coty lary of the remaining cotyledon grew even in the plants deprived of the root.

The effect of glycine on the growth of isolated tomato roots in White's nutrient solution was studied. It is obvious that the root tips grow better in the medium without glycine, because increasing rates of glycine produce inhibition. The growth of root explantates in nutrient media indicates a high synthetic ability of isolated roots. Optimal concentrations of humus acids in White's nutrient solution without glycine and with glycine stimulate the growth of root explantates. It cannot be decided which of the two substances affects the root directly and which acts as a chelating agent in the medium. The effect of glycine varied, depending on the origin of sucrose used. It appears that in media containing beet sucrose, glycine is unsuitable but in media containing cane sucrose it is necessary.

Changes in the percentage of seed germination, the growth and respiration rate of the seedlings were observed at 15-day intervals from the stage of the full germination capacity of rice (Oryza saliva L.) seeds till they became non-viable. At the beginning, the respiration rate changed but little, but afterwards, with the approach of non-viability, the rate declined sharply. A positive correlation of respiration with a decrease in the germination percentage and the length of seedlings and a negative correlation with days of storage were also established. A strong correlation existed between catalase and peroxidase activity with respiration, indicating that the activity of these enzymes can be used as an indicator of metabolism, and therefore can be considered as part of the respiratory mechanism of rice seedlings.

The influence of photoperiodic induction on the incorporation of uridine-³H into the shoot apices ofChenopodium rubrum was studied using the technique of autoradiography. No increase in uridine incorporation was detected either during induction lasting three days or immediately after its termination. Pyroninophylia likewise did not rise. However, changes in uridine incorporation related to morphogenetic activity during leaf formation and later during differentiation of inflorescences were well marked. The distribution of label in the nucleus immediately after three inductive cycles shows the ratio of extranucleolar to nucleolar incorporation to be higher in non-induced control plants than in induced ones.
Data from literature pointing to an activation of RNA synthesis during transition to flowering are discussed and compared with other systems where ontogenetic changes are accompanied by marked changes in RNA synthesis. It is assumed that the activation of RNA synthesis after induction is connected mainly with the activation of growth. However, inChenopodium rubrum photoperiodic induction proceeds together with limited growth and without activation of RNA synthesis.

The nucleic acid fractions in cotyledons of young Chenopodium rubrum plants exposed to continuous light, continuous darkness and short (8 h) day, respectively and labelled with³²P 24 h prior to harvesting were studied by means of chromatography on MAK columns. Some parameters of cotyledon growth (dry weight, cotyledon area, occurrence of mitoses) were also investigated.
The changes in the nucleic acid fractions agreed with the dynamics of cotyledon growth. In continuous light the content of all fractions increased. The radioactivity of DNA and s-RNA did not undergo any great changes and only r-RNA increased. The specific activity of r-RNA increased slightly, that of soluble RNA and DNA was reduced. In continuous darkness the content of all the fractions did not undergo any great changes. The radioactivity as well as the specific activity of all fractions decreased. In short day the content of the nucleic acid fractions did not change conspicuously. Only the specific activity of s-RNA increased in a noticeable way while the radioactivity of r-RNA and the specific activity of DNA decreased and this of r-RNA did not change. The changes in nucleic acid metabolism were partially connected with changes in³²P uptake which depended upon light conditions but they were not merely a consequence of this fact. Obviously, there also exists a more direct relationship between nucleic acid synthesis and growth.

The cotyledonary petioles inPisum sativum developing at the start of germination, as well as the cotylaries growing out after decapitation of thePisuin seedlings manifest very often the so-called lateral correlations, since one of them suppresses the opposite primordium when the growth inhibition in the plant coinciding apparently with the growth promotion results necessarily in a normal development only of one of these originally equal primordia. These correlations also seem to be mediated by auxin, being induced by gravity or by corresponding cotyledon and root products, which can be supported by the use of exogenous auxins.

Decreased accumulation of elements, particularly of nitrogen, had in dense stand a negative influence on the plants, in spite of the supply of fresh solution and the control of the concentration of nutrients in the pots. The fresh weight and the dry matter of one plant were reduced substantially with rising stand density (from 5 to 10, 20, 40 and 80 plants per 450 sq. cm); the RGR value, the relative absorption rate I_M, the content of all tested elements calculated per one plant, the chlorophyll content in the overground parts of one plant, and the distribution index decrease. Qualitatively the same influence is caused by deficiency of nutrients. Plant dying and self-thinning of the culture occurred in denser stand in the course of cultivation. The root-weight ratio rose with stand densification, particularly at the end of the experiment. The net assimilation rate (NAR) related to chlorophyll dropped with stand density; NAR at density "80" rose slightly from the 22nd day of cultivation and did so at further lower densities. Almost all NAR values lie over the control value at the last measurement. The chlorophyll content in mg g^-1 dry matter of the overground parts rose with stand density to density "40" (41% more than at density "5"); afterwards it dropped. The accumulation (in mg g^-1 d.m.) of phosphorus ions was higher in the plants from dense cultures compared with density "5", particularly in the roots. The accumulation of potassium was near to the control value ("5"), while that of nitrogen was lower. The utilization quotients of phosphorus and potassium in denser stands were the same or negligibly lower than at density "5". They were a little higher in nitrogen than in the controls. Also the ratio RGR/I_M was a little higher than in denser stands. The root-weight ratio, the accumulation of elements in mg g^-1 d.m., the chlorophyll content in mg g^-1 d.m., NAR_ch, the utilization quotient, and the ratio RGR/I_M differed qualitatively by the densification of the culture (with complete mineral nutrition) from the influence of element deficiency (at the same stand density).

In order to interpret the mechanism of elongation growth of the hypocotyl with radicle in the first stages of germination of the pea seed (Pisum sativum L.) a cybernetic model utilizing feed-back as a mechanism of correcting the wrong direction of growth was proposed (Spurný 1966, 1967). In the present study, the effect of amputation of the root tip as the control centre on the trajectory of the growing radicle was investigated. The results have shown that the hypocotyl grows, elongates-the rate of growth being slightly lower than that of the standard, but that no spiral oscillations at all are executed by the organ after amputation of the root tip. This finding appears to confirm the applicability of the proposed cybernetic model, for amputation of the root tip means that not only the control block is eliminated, but also that the channel of feed-back impulses to zone of elongation is interrupted.

Investigations were made on the effect of exposing barley seeds to gamma-radiation (5-40 kR), alone and in combination with the application of zinc (soaking the seeds in solutions containing 5.10^-5-5.10^-1% Zn for 12 hours before sowing) on growth and on the content of tryptophan, indole auxins and gibberellin-like substances in seven-day plants. Radiation decreased both growth and the content of tryptophan (e.g. by about 53% at 30 kR), of indole auxins (by about 60% auxin in the zone of IAA on the chromatogram at 30 kR), and also the content of gibberellin-like substances (by about 67% gibberellin content in the zone of GA₃ on the chromatogram) of plants. The irradiation of standard samples of tryptophan, indolyl-acetic acid and gibberellic acid alone with many times greater doses (up to 1000 kR) did not lead to marked radiochemical degradation of these substances. It can be assumed that radiation damages the enzyme systems "synthesizing" natural growth substances in plants. The damaging effect of radiation on auxins is already displayed in the synthesis of tryptophan, which is inhibited.
Zinc interacts with the damaging effect of radiation on growth. Optimum concentrations of zinc (5.10^-3% Zn) counteract the effect of radiation, up to doses of about 12 kR, on the growth in height in 7-day plants so that it is equal to the controls. Normal content of tryptophan and auxin in the position of indolecetic acid on chromatograms can only be reached by the addition of zinc when the dose of radiation was not greater than about 8 kR, which is less than the influence exerted by zinc on the restitution of growth. On the other hand, the biosynthesis of gibberellin-like substances at the position of gibberellic acid on chromatograms can be restored by zinc to their original level to doses of up to 30 kR. The increased biosynthesis of auxins and gibberellins caused by zinc in irradiated plants is explained by the activation of the remaining and non-damaged enzyme systems carrying out this biosynthesis. The activation of the biosynthesis of growth substances by zinc will also contribute to the restitution effect of zinc on the growth of plants from irradiated seeds.

Physiological effects of volatile substances released by the overground as well as by the underground organs of higher plants were studied. The activity of the volatile substances was tested both when these substances were allowed to act directly in the air and when they were dissolved in water in the form of solutions. Plants which do not contain essential oils or which are not rich in them as well as those abounding in essential oils and other volatiles were used in the experiments. The physiological activity of the volatile substances was tested on rye seedlings.
The overground as well as underground mature organs of the tested plants were found to release volatile substances causing, when acting directly, in the majority of cases an inhibition of the growth in length and of the formation of dry matter in rye seedlings. A pronounced inhibition of the growth of rye seedlings was brought about especially by the volatile substances of "aromatic" plants such as common dill, wild thyme, yarrow milfoil, garden thyme, marjoram, etc. The volatile substances released by the organs of "non-aromatic" plants like sugar-beet, common sunflower, quackgrass, etc., were found to bring about a significant inhibition of the growth of rye seedlings, too.
The volatile substances released by the plant organs were found to be altogether absorbable in water and physiologically active also in the form of water solutions. With the exception of volatile substances from hemp and quackgrass leaves, which brought about a mild stimulation of the dry matter formation in rye seedlings, inhibitory effects of these solutions were found to prevail in all cases. Most effective were the solutions of the volatiles from some of the "aromatic plants".
An assay for olefines in the atmosphere of the experimental vessels demonstrated that in almost all cases ethylene is being released by the plant organs.

The aim of the present investigation was to examine whether some of the growth defects of calcium-deficient pumpkin (Cucurbita pepo L.) seedlings are due to an incapability of the plants to assimilate nitrate nitrogen, such being the mechanism by which according to some of the previous authors growth defects in calcium deficient plants may be produced. The results of the present study, however, demonstrate that the accessibility of various possible products of nitrate reduction is not the limiting factor responsible for growth symptoms of calcium deficiency.

We have found in a number of plants (lentil, lupine, bean, barley, oats, rye, wheat, cucumber, melon, flax, sunflower and rape) that varying amounts of ethanol are formed under natural anaerobiosis and, that in later growth periods these plants continue to react to anaerobiosis by formation of ethanol. When the testa has opened in germinating plants or, when plants are transferred from the anaerobic atmosphere to air, ethanol disappears.
Plants contain alcohol dehydrogenases, the activity of which depends on the alcohol concentration in their tissue; the maximum concentration is reached during natural anaerobiosis, rising in the course of further growth when the plants are kept in a nitrogen atmosphere.
Alcohol dehydrogenases of the plants studied are localised in the soluble cell fraction notsedimenting at 120 000 g, their pH optimum is in the weakly alkaline region and their Michaelis constants are equal in order of magnitude (10^-5m). They are all inhibited in the same way by Zn²⁺, Cu²⁺, Hg²⁺, B₄O₇^2- ions, p-chloromercuric benzoate, iodoacetate, EDTA and phenantroline, which may be considered as evidence of the presence of -SH groups. The specific activity of alcohol dehydrogenase preparations is higher in plants grown in light than in plants grown in the dark.
The specific activity of plant alcohol dehydrogenases can be increased by precipitation with ammonium sulphate by at most one order of magnitude, while all the activity is lost by this purification process in the case of cereals.
The following isoenzyme composition of ADH was found by means of electrophoresis on polyacrylamide: the enzyme from poas and sunflower, for example, is composed of three, that from wheat and oats six, the enzyme from maize and barley of five isoenzymes.

The influence of penicillin in concontrations of 8.3-10,000 IU/ml on algaChlorella pyrenoidosa was studied. Depending on temperature, the concentrations of 14 to 6,000 IU/ml have a stimulating influence on algal growth which may go as far as 1572% as against the control. The differences in temperature (15° to 18°C or 25° to 28° C) and in the concentration of mineral substances in the Knop solution employed do not affect the mode of action of penicillin, but affect the absolute production of algae whose maximum lies between 2,500 and 3,000 IU penicillin/ml.

Isozyme patterns and specific activity of ribonuclease (ribonucleate pyridinenucleotido-2'-transferase, E. C. 2.7.7.16) were followed in the extracts of segments from three growth zones of the root and in extracts of young and senescent leaves ofVicia faba L. Electrophoreograms of extracts from all three investigated root zones were identical, in the electrophoreograms of extracts from senescent leaves however one new ribonuclease occurred which could not be detected in the electrophoreograms of extracts from young leaves. Extracts from senescent leaves had higher specific activity of ribonuclease than extracts from young leaves. Extracts from the enlargement zone of the root and those from the maturation zone had a three times higher specific activity of RNase than extracts from the division zone.

Flowering in the short day plantChenopodium rubrum was inhibited by 5-fluoro-deoxyuridine (FDU) at a concentration of 4×10^-6 M and higher when applied during photoperiodic induction or immediately afterwards. This inhibition is always accompanied by a general reduction of growth (e.g. a decrease in the first leaf length). The mitotic activity within the shoot apex is completely blocked by FDU application during the photoperiodic treatment. The floral induction (evocationsensu Evans) was not cancelled in this situation as was revealed when reversing the FDU effect by thymidine application. One day after the end of the photoperiodic treatment (the plants were transferred to continuous light again) the FDU inhibition becomes irreparable. The results indicate that DNA synthesis and hence the mitotic activity are not obligatory prerequisites for photoperiodic floral induction inChenopodium. Low concentrations of FDU may promote flowering under suboptimal floral induction.

In experiments from 1966-1968 a comparison was performed concerning the level of endogenous stimulators and inhibitors in leaves and shoots of peaches decapitated in three different times and in controls.
For the determination of these substances a biological test was employed after separation of the acid fraction of ethyl ether extracts by means of paper chromatography. Mathematical addition of total stimulations and inhibitions gave a new value, called "growth disposition" by the authors. Its graphical demonstration gives a simple curve which documents the growth rhythm of control plants as well as the response of plants to the time-regulated decapitation. In the case of shoots this response has always been positive,i.e. at all periods of sampling for analyses the growth disposition with decapitated plants was higher in comparison with controls.

Changes in water uptake immediately following the application of high concentrations of 2-methyl-4-chlorophenoxyacetic acid (MCPA) into the root medium of whole plants ofPisum sativum andVicia faba were investigated potometrically under controlled conditions. It was found that concentrations between 10^-2 and 10^-5 m bring about a sudden, pronounced and lasting inhibition of water uptake. Its rate depends directly on MCPA concentration. At 10^-2 m, sudden inhibition of water uptake becomes apparent as early as 10 min after application. With decreasing concentrations the appearance of inhibition is retarded but the inhibition is still sudden and well-pronounced. The inhibition of water uptake observed after MCPA application to the root medium of whole plants agrees with the sudden striking reduction in transpiration intensity observed byAllerup (1964) after the application of similar concentrations of 2,4-dichlorophenoxyacetic acid. The presence of MCPA in the nutrient medium causes inhibition of water uptake even in cut plants. Its rate again depends on the concentration of the growth substance. The inhibition does not appear here as quickly and is not as sudden and pronounced. High concentrations of MCPA during application to over-ground plant organs do not bring about immediate inhibition of water uptake by the root.

Time doses of a single concentration of streptomycin and its concentration doses acting for the same time period in a liquid medium had different effects on three strains of chlorococcal algae. This concerned both the physiological responses and permanent changes in the characteristics of cell colonies growing from treated cells. Significant differences were recorded in: the number of autospores produced during the first division of the treated cells on the surface of a solid medium, the length of the lag phase, the growth rate of the diameter of cell colonies, and the survival of the treated cells. The permanent changes in the characteristics of the growing colonies were very different in the individual algal strains in quality and frequency. Physiological and the mutation effects were compared and discussed.

It was found by measuring the length of the cortex cells of the root tips of the broad beanVicia faba L. that the beginning of the elongation zone lies at about 1-2 mm from the initials and its end at about 7-8 mm from the initials. Shrinkage of the object during microtechnical treatment was negligible. The autonomy of the individual tissues of the root tip was taken into account.

The differentiation of tissues is closely connected with the proteosynthesis. One can therfore assume that tissues with different types of cell growth (meristematic or elongation growth) and with different degrees of differentiation are different in their protein composition. In order to compare the protein composition of different plant organs, the method of disc electrophoresis on a polyacrylamide gel has been used by some authors. As compared with other methods used up to now, e. g. isolating proteins on DEAE cellulose or in Sephadex, this method does not need so much material and its resolution ability seems to be higher. It is also quicker and enables the study of several samples simultaneously. Its disadvantage is that proteins can be identified mainly by means of Rf and their quantity, measured from the intensity of staining of individual fractions in the gel, which may be misleading due to different sorption capacity of different proteins (FričFričová 1967). None the less, it is good for comparison of protein composition of individual parts of the plant body.
Different methods have been used to compare protein composition of individual growth zones in roots.Barsky,Ivanov andPushakova (1965) used luminiscence microscopy and found that in maize roots it is not possible to find substantial differences by this method.Morgan andReith (1954) arrived at similar conclusions. On the other hand,Steward et al. (1965) andMorris (1966) found qualitative differences in protein composition of different parts of pea roots using acrylamide electrophoresis. The results of the last named authors show considerable discrepancies in details, due perhaps to a different method of extraction (buffer, pH, purifying method).
We have used acrylamide gel electrophoresis for investigating proteins in precisely defined growth zones of theVicia faba root.

1) At a so-called natural anaerobiosis during the first 48 hours of germination the concentration of ethanol in pea tissues increases (according to the cultivation conditions) up to 40 μmol per gram fresh weight.
2) In a nitrogen atmosphere the content of ethanol in pea seedlings increases as well, and after a 90 hour incubation in N₂ it can reach even 100 μmol ethanol per gram fresh weight. In older plants the content increases the most markedly in cotyledons, but considerable amounts were revealed also in stems and roots. Its increase in vegetative organs of plants cultivated both in light and darkness is more or less identical. Ethylalcohol can be formed by the vegetative organs themselves, as proved by the increase of this metabolite in plants deprived of reserve organs; in addition, however, it is evidently transported into them from reserve parts. Ethanol formed under anaerobiosis is catabolyzed after transferring plants to the air.

Evidence for the effect of sterols on plant mycoplasma is presented. Two essential sterolsi.e. cholesterol and stigmasterol were applied in the following way: grafts from tomato plants infected with potato witches'broom, wedge-shaped at the base were dusted on the cut surfaces with the corresponding sterol in the amount of 4 mg to one graft, inserted in freshly cut wedges of stock plants and firmly tightened with rubber tubes. Both sterols stimulated growth of diseased grafts and delayed symptom manifestation. The stimulation was more evident with stigmasterol and the delay in symptom manifestation and intensity was more distinct with cholesterol. Supplying tomato plants with sterols externally probably enables additional multiplication of mycoplasma in already infected grafts, and the plants need not provide the grafts with essential metabolites which they themselves need for the development of reproductive organs. Stigmasterol, a metabolite peculiar to the tomato plant, is probably more rapidly consumed than cholesterol which may remain in the plant as a metabolic pool of sterols for mycoplasma propagation.

For three consecutive years the content of natural stimulators and inhibitors was observed in leaves and shoots of peach trees. Research was directed to the question of development of flower buds.
The substances under study were isolated from the acidic fraction of ether extracts by means of paper chromatography and their concentration was determined by biological test. The activities of substances which either stimulate or inhibit the growth of oat coleoptiles, were added up. The curve expressing the content of stimulators in shoots in relation to the fresh weight showed its maximum in the period of full growth of shoots (15 June-15 July according to the fluctuating vegetative conditions) and it showed a decreasing tendency at the end of the season. The decline of the curve showing the content of inhibitors is of similar direction but less steep. The trend of substances under study is the same in leaves as in shoots, but their quantity is lower. Stimulation and inhibition effects in individual sampling intervals were added up to make a common curve which seems to express the combined action of stimulators and inhibitors in the plant, which determines its growth pattern.

CCC (2-chloroethyl)trimethylammonium chloride applied to plants ofChenopodium rubrum during floral induction led to an increase in the level of endogenous cytokinins in the apical buds. Application of gibberellic acid or indole-3-acetic acid at concentrations reversing the effect of CCC reduced the level of cytokinins. After simultaneous treatment with both CCC and one of the growth substances this reduction was less pronounced. From the comparison bf the present results, as well as of those published in previous papers it follows that in apical buds ofChenopodium rubrum there exists a mutual interaction between gibberellins and cytokinins. Under certain conditions both these groups of hormones may substitute for each other in flowering. IAA seems to affect flowering by regulating the level of both gibberellins and cytokinins.

The methyl-ester of 2-chloro-9-hydroxyfluorenole-9-carboxylic acid (Chlorflurenol-Methyl =CFM) enhances the elongation of intact plants ofColeus blumei and induces leaf curvatures and an anormalous abscission of the youngest leaves. In long-time-experiments (3-4 month), CFM induces increased outgrowth of the axillary buds including leaf deformations and abscission of organs on the originating shoots. CFM stimulates the adventitious root formation of cuttings fromHelianthus, Phaseolus, andColeus. It is shown inColeus cuttings that an inhibition of root formation precedes the stimulation of root formation. Gibberellic acid does not influence any one of CFM-induced effects. Therefore morphactins are not GA₃-antagonists. TIBA qualitatively causes the same effects as CFM. Therefore it is possible that the mechanisms of actions of both substances are similar.

The metabolism of D-and L-tryptophan-3-¹⁴C (Try-3-¹⁴C) was studied and compared for three different plant species, cabbage, maize and pea. Apical segments of the seedlings were incubated for 6 hours in solutions of L- or D-Try-3-¹⁴C (1.5 μc/ml) with the addition of chloramphenicol (10^-4g/ml) and then allowed to stand for another 20 hours in moist chambers. The methanolic extract of the tissues was analyzed radiochromatographically and by paper electrophoresis in combination with biological tests. Chloramphenicol in a concentration of 10^-4 g/ml had little influence on the growth of the segments, though the antibiotic slightly decreased the uptake of L-Try, it did not prevent the formation of IAA from L-Try. In the segments of cabbage the following metabolites were formed from L-Try-3-¹⁴C (accounting for 52% of the activity of the chromatographically separated extract): glucobrassicin (26.0%), neoglucobrassicin (3.6%), a spot corresponding according to its Rf to 3-indolylacetamide (IAAmide-10.9%), β-glucoside of 3-indolylacetic acid (IAGluc-3.3%) and traces of 3-indolylacetonitrile (IAN), IAA and indole-3-carboxylic acid (total 5%). In maize segments L-Try-3-¹⁴C (53.0%) was transformed to several unidentified hydrophilic substances, one of them possessing auxin activity (total amount 6.9%), IAGlue (9.3%) accompanied by a small amount of tryptamine, a spot corresponding according to its Rf to IAAmide (16.5%), IAA and another unidentified hydrophobic substance (4.1%). In pea segments L-Try-3-¹⁴C (66.7%) gave a zone corresponding according to its Rf to IAAmide (20.0%), a substance similar to IAGluc (10.5%) and also hydrophobic substances (3.1%) containing traces of IAA, which could be demonstrated only by bioassay.
D-Try is metabolised in the three plants by the virtually exclusive formation of malonyltryptophan.

Changes in soluble sugar content in individual parts (embryo, endosperm and pericarp) of maize caryopses exposed to the influence of 24°, 10° and 6° were studied. At the same time the eluates from sand in which the seeds were planted and exposed for various periods were analysed by paper chromatography.
It was found that the lower was the temperature of exposure the greater were the amounts of sucrose, glucose, raffinose and other sugars diffused from the caryopses into the medium before the start of germination. The exosmose course and the changes in sugar content in kernel tissues proved that the hydrolysis of storage polysaccharides is not inhibited by low temperatures but that under such conditions the use of products of hydrolysis for the growth of the embryo is inhibited.
It is concluded that not only surface parts of endosperm but also the embryo participates in exosmose. The relatively high sugar exosmose found from seeds germinated at low temperatures explains the well-known interaction of pathogenic and parasitic microorganism in cold resistance during emergence.

The paper deals with the effect of mineral nutrition on the content of free flavonoid glycosides (phloridzin, hyperine) free and bound C₆-C₁ aldehydes (vanillin, syringic aldehyde) in the woody parts of apple shoots of the variety 'Antonovka' and on the content of products oxidized by nitrobenzene (vanillin, syringic aldehyde) in connection with the lignification of cell walls.
It was established that the biosynthesis of phenolic compounds is retarded under the influenco of nitrogenous fertilizer while the biosynthesis of proteins is activated, intensifying growth. Contrary to nitric fertilizer, phosphoric with potassic fertilizers promote formation of phenolic compounds and suppress protein synthesis and growth; at the same time phenylalanine is included in the biosynthesis of lignin, but not in the biosynthesis of proteins.