1. Difference in sowing date influences the development of winter wheat. The earlier the sowing, the earlier is the completion of the thermostage. The length of the thermostage of early sowing wheat is longer than that of the later sowing wheat. The length of photostage is affected in the opposite manner. 2. Differentiation of the growing cones of early sowing wheat is faster than the later sowing wheat, but the differences became smaller as growth proceeded. 3. Early sowing produces different effects on the development stages and the differentiation of the growing cone. Thus, winter wheat might complete the photostage while the growing cones were in the double ridge stage. 4. A discussion on the relation of the differentiation of growing cones and the development stages, also on the influence of sowing date to the yields were presented.

The parasitic genus, Melanocolax, which is represented only in South Africa, was established by Martin et Pocock (1953), who assigned in it a single species: M. velutina. M. velutina is a parasite of Rhodomelopsis africana Pocock; it gives rise to branched monosiphonous filaments within the infected tissues but produces velvet pustules to the external of the host. From the surfaces of these pustules, free fertile branchlets are produced. The present paper deals with the developmental history of female and asexual reproductive organs of M. velutina; material of which species, used in this study, was furnished by Prof. G. F. Papenfuss, to whom I am much indebted.

Trichoderma koningi Oudemans (3.2064), a cellulose-decomposing fungus isolated from rotten corn kernel, has been screened from more than 100 strains of fungi belonging to the genera of Trichoderma, Chaetomium, Stachybotrys and Myrothecium. Attempts have been made to study the physiology of T. koningi with reference to its practical application to the fermentation of industrial and agricultural by-products as well as wild plant materials. The results were obtained as follows. The decomposition ratio of straw cellulose by T. koningi was 32% and 50% for 3 days and 9 days respectively. The saccharifying ability of the fungus on wheat straw is rather high and the reducing sugar was determined to be 29 mg/g per hour. Evidence have been obtained to show that T. koningi may produce antibiotics resembling viridin and gliotoxin, both in liquid medium and mycelia. Such Trichodermafeeds are non-poisonous or harmless when fed to animals after bolling. Mycelial growth has been found to occur between 15–40 ℃, and to cease at 10 ℃ and 45 ℃, the temperature for the most rapid mycelial growth being about 36 ℃. Under the conditions in forage fermentation, the accumulative temperatures for spore germination, mycelial development and sporulation have been found to be 61, 153 and 380 hourdegree (C.) respectively. The relative humidity most favorable for mycelial growth is 98%, and the growth ceases when the relative humidity is below 92%. The pH range favorable for mycelial growth on liquid medium is from 4.0 to 7.5, the optimum being about pH 6.0, and no growth occurs at pH 2.5 and pH 9.0. T. koningi is capable of utilizing d(+)mannose, d(+)glucose, d(+)xylose, cellubiose, dextrin, maltose, fructosan and fructose; glycerin, fumaric acid, puruvic acid and d(+) galactose rank next in utility; soluble starch, d(-)arabinose, d(-)erythrose, lactose, suc- rose, raffinose, d(-)ribose, dihydroxyacetone, agaragar and L-rhamnose are poor carbon sources for this microorganism. Among these compounds, fructosan and sucrose are very effective for sporulation. The fungus is capable of utilizing both organic and inorganic sources of nitrogen, but the former seems to be better for assimilation. Among amino acids, L-glutamic acid and L-tryptophan are the most favorable for mycelial growth, on the contrary, the aromatic acids and the amino acid containing sulphur are least assimilable as nitrogen sources for this fungus. L-Glutamic acid, asparagin and DL-valine are the most favorable for spore production.

It is known that treatment with boron may to a certain extent reduce the percentage of boll shedding in cotton plant. It is also known that boron plays a special role in carbohydrate metabolism of the plants in general. The present work attempted to elucidate the effect of boron treatment on the translocation and metabolism of carbohydrates in cotton plant. The first internode of the fourth to the sixth fruiting branch of field grown cotton plant was chosen as experimental material. Only one leaf and one newly-opened flower were left on the branch. Ringing was performed 3 cm below the flower in order to localize the treatment effect. Boron treatment was either applied to the leaf or to the flower. Treatments were either done in the light, or when plants were kept in darkness. At various intervals (24 and 48 hours) after treatment, samples were taken, each sample being constituted of 15 branches. Reducing sugars, sucrose and starch were determined respectively. Experiments showed that starch made up 10%–13% of the dry weight of cotton leaf, it made up 5%–6% of the dry weight of the young boll. Boron treatment of the leaf did not only increase the content of starch and reducing sugars of the treated organ, but also increased the content of reducing sugars of the boll opposite to the treated leaf. When plants were kept in darkness, boron treatment of the leaf increased the content of reducing sugars of the treated leaf at the expense of the content of starch. This treatment caused an increase of both starch and reducing sugars in the boll. It is considered that the beneficial effect of boron on boll shedding is related to its improved carbohydrate supply to the boll.

The PAS reaction is applied in staining cellulose cell walls and starch grains in plant tissue preparations. Different kinds of fixatives used in combination with this method yielded equally good results. Various trials were made to obtain satisfactory results for PAS reaction in plant tissues. Procedure with 10 min in 0.5% KIO4 followed by 30 min. in Schiff's reagent gave a suitable coloration. Cellulose walls and starch grains were colored cherry red or reddish purple. Counterstaining may be used if desired. Iron-alum haematoxylin, methyl green and orange G were used as counterstains with satisfactory results. Advantage is taken of the fact that lengths of time required for acetylation of cellulose and that of starch are different. Thus starch and cellulose can be stained differentially. Several kinds of plant materials including root and shoot apexes, stems and cotyledons were used as examples to demonstrate the results of employing this method.

The present paper deals with in vitro culture of immature sunflower embryos. The basic medium consists of modified White's medium, supplemented with thiamine 1 ppm, pyridoxine 1 ppm, nicotinic acid 1 ppm, Ca-pantothenate 0.5 ppm and glycine 3 ppm, and 4% sucrose and 0.8% agar were used throughout all the experiments. IAA and coconut milk (autoclaved) at different concentrations used singly or both mixed in various combinations were studied for their effect on embryo growth. The embryos isolated were about 5 mm in length and they usually germinate precociously when inoculated on the culture medium. The results are summarized as follows: 1. IAA (0.05–20 ppm) is stimulatory on the embryo growth as shown in the increase of fresh weight of the treated embryos. IAA is effective in inducing embryo callus. At the concentration of 1 ppm there are about one fourth embryos producing callus, at 5 ppm, about two thirds of embryos, and above 10 ppm, 100% embryos forming callus. IAA is stimulatory on the formation and growth of the root at low concentrations (0.05–0.1 ppm), but it becomes inhibitory on the root growth at higher concentrations (10–20 ppm). 2. Coconut milk (autoclaved) has definitely a pronounced favourable effect on the shoot growth of the embryo and it inhibits the root growth. Both effects are particularly conspicuous at the stage of two weeks old culture, thereafter the difference between the control and the treated embryos gradually becomes insignificant. Coconut milk is also effective in inducing embryo callus but it is not so effective as IAA. 3. The effects on growth and induction of embryo callus become more pronounced when IAA and coconut milk are mixed in various combinations for treatment. There are certain similarities between the effect of coconut milk and that of IAA but it is im- probable that the effective substance in coconut milk is only an auxin.

Decaisnea fargesii Franch. is one of the rubber plants which have received considerable attention in recent years. The rubber of Decaisnea fargesii occurs only in the laticiferous canals of the pericarp and there is neither laticiferous canal, nor rubber substances in its roots, stems and leaves. In the present paper, a preliminary result on the research of the structure and the ontogeny of the laficiferous canals of Decaisnea fargesii is reported. In the pericarp of the mature fruit, an aggregate fleshy follicle, of Decaisnea fargesii, there are numerous white colored laticiferous canals which are easily recognized with the naked eye. These canals connect with each other to form a reticulum. The fundamental structure of the pericarp of the young flowers is not different from that of other flowering plants. However, the protoplasm of the outer epidermal cells of the pericarp is more dense and it takes stains more deeply than that of the cells of its inner side. After the blooming fertilization, numerous spots on the outer epidermis of pericarp become centers of activity. There the cells begin to divide more actively than the other portion. As a result, numerous minute papillae are simultaneously formed. As the cells continuously divide, the papillae are gradually elevated and enlarged. At the bases of these papillae are depressions which become canal-like structures. These connect to form a reticulum below the surface of pericarp. When the canals reach a depth of 200–300μ, the divisions of the epidermal cells flanking the canals gradually slow down, but these cells increase in volume. Because the cells enlarge in anticlinal direction much more than in periclinal direction, the canals become narrower and narrower as the cell enlargement continues. Finally, the lateral walls of the canals meet each other and become fused. Here after enlargement of the epidermal cells are restricted to the lower portion of the canals. The whole structure viewed in cross-section is like a flask. At this stage, the epidermal cells in the lower portion of the flask-like structures are characterized by their larger in volume, larger nucleus, denser-protoplasm and smaller vocuoles. The chloroplasts formerly present disappear and some deeply stained particles appear in the protoplasm. Therefore, the morphology and the structure of these cellgroups are quite different from other epidermal cells of the pericarp including those on the surface and in the upper portion of canals. These groups of cells may be called secretory epidermal cells. At the end of the cells enlargement, the secretory epidermal cells of the lower portion of the canals separate each other and their walls begin to disintegrate. As these activities extend to every part of the secretory epidermal cells, a lysigenous intercellular canal is finally formed. The epidermal cells of the upper portion of the flask-like canals remain intact thus burying the canals formed in the mesocarp of the fruit. The protoplasm and inclusions of the disintegrated cells assume the appearance of milky fluid in the canals. Thus these canals should be regarded as laticiferous canals. During the further development of the pericarp, 2–4 layers of parenchymatous cells of the mesocarp surrounding the disintegrated epidermal cells break off. This makes the diameter of laticiferous canals to be further enlarged. In general, the ontogenetic processes of the laticiferous canals of Decaisnea fargesii include (1) elevation of the external epidermal cells of pericarp, (2) depression of the epidermal cells in the peripheral zone of the papillae, (3) formation and burying of the canals, and (4) disintegration of the secretory epidermal cells. Such a complex phenomena in formation of the laticiferous canals of Decaisnea fargesii is the special type in intercellular canals of plants. Within the pericarp of fully matured fruits, the diameter of the laticiferous canals may reach 600–800μ and their structure resembles the schizogenous intercellular canals generally occurring in other plants in which no special peripheral sheath-like cells has been observed. They remain in the mesocarp, covered externally by 6–9 layers of cells and form a reticulate system parallel with the outer wall of the fruit. According to the present analysis on their structure, ontogeny and distribution, the laticiferous canal system of Decaisnea fargesii is obviously different from the laticiferous tubes and the intercellular canals usually observed in the other plant. Their special type of formation is probably connected with the localization of their occurrence and particularly in relation with the characteristics of development of the fleshy fruit.

In autumn the subterranean stems (stolons) of stachys sieboldii Miq. form tubers on their tips, resembling the formation of tubers in potato plants. However, if the tips of stolons were cut at various lengths and were cultured in artificial medium at the end of summer, these segments continued to grow. They gradually lost the original characters of the stolon and developed into the normally upright stems. Meanwhile, numerous adventitious roots were formed at the base of the cuttings, until a well-developed root system was established. The initiation and development of adventitious roots were intimately related to the length of the original stem-tip segments. The highest percentage of the initiation of the adventitious roots was obtained when the segments undertaken contained 5–6 internodes, whereas those with only 3 internodes showed no apparent growth. After four weeks of culture, a full plant was developed from the isolated segment. This newly formed “seedling” was covered with fairly dense epidermal hairs. The stem became square from which dark-green decussate foliage leaves developed. A well-developed root system was formed from the adventitious roots near the cut surface. After eight weeks in culture, the apexes of these already established upright stems became swollen and transformed into tubers of various sizes. Such tuber formation is different from that under natural conditions. At present, it is rather difficult to interpret such phenomenon by any known hypotheses of tuber formation.