The Homudu site was discovered closed to the northeastern part of the village Homudu in the Lochiang Commune of Yu-yao zhejiang sheng. The excavations were conducted in 1973–1974 and 1977–1978. Four layers of cultural deposits are super-posed one upon the other. The first and topmost layer corresponds to the middle layer at Sun-tse in Ch’ing-p’n Country, while the second layer represents the Ma-jla-bin Culture of Chiahsing Country. The third and fourth layers belong to a hitherto unknown culture, which has been provisionally named as the Homudu Culture. A palynologicai and paleobotanical study is made for showing the paleovcgetation and palcoclimate of that time. 1. The first sporo-pollen assemblage, obtaind from the fourth and lower part of third layers is marked by predominence of Gramineae pollen (11%–71%). The majority of Gramineae pollen is of large size. Exine is thin and more psilate. Annulus of the single pore is about 2.5–3.7 μm in wide. This kind of pollen very much resembles that of the recent rice (Oryza sativa). Besides that, the herbaceous pollen of Artemisia, Caulophyllum, Actinostemma, Polygonum, Rubia and some elements of Cyperaceae,Chenopodiaceae, Umbelliferae are noted. Pollen of trees and shrubs belong to Quercus, Castanopsis, Liquidambar, Mallotus, etc. Fern spores are of Lygodium. Ophioderma, Lemmaphyllum, Microsorium and Pyrrosia. A lot of plant remains (leaves and seeds) have been observed in the fourth layer: Chloran- thus fortunei, Magnolia coco? Phoebe sheareri, Lindera glauca, Camptotheca acumninata Prunus davidiana, Choerospondias axillaris, Trapa bispinosa, Quercus myrsinaefolia, Cas- tanopsis tibetana, etc. Sporo-pollen assemblage and plant remains reflect a subtropical everygreen and deciduous broad-leaved mixed forests flourished on mountain slopes and some rice fields scattered in the plains around the site. The climate of that time was warm and humid and rather warmer than that of the present. Radiocarbon tests of an acorn and a wood fragment unearthed from the fourth layer reveal that they date from about seven thousand years ago, corresponding to the Atlan- tic period of Europe. 2. The second sporopollen assemblage, obtained from the middle and the upper parts of third layer is predominent by pollen of trees, such as Quercus spp., Liquidambar formosana and others. In herbs, the pollen of Gramineae, Cypcraceae and water plants deereased, but those of Artemisia and Chenopodiaceae increased. The climate than was warm but somewhat drier than that of previous period. 3. The sporo-pollen assemblages from the second and the first layers were mainly composed of temperate elements, such as Quercus, Ulmus, Salix, Where the subtropical elements Liquidambar and Altingia decreased or completely disappeared.. These indicate that the climate become cooler than that of the previous periods. Radiocarbon tests of a wood fragment obtained from the second layer reveal that its date was from 5600 years ago, then the age of the second layer would correspond to the Subboreal period of Europe. A lot of rice pollen grains, along with a large amount of the remains of rice busks were obtained from the fourth layer in the site, which indicats that the rice plants were cultivated in China at least seven thousand years ago.

This paper mainly deals with the Upper Cretaecous-Paleogene and the Neogene floras of Xizang. In 1974–1976. the Scientific Expedition Party of Academia Sinica discovered some fossilbearing beds from the Rikaze Group of Angreg district, the Jiuwu Formation of Douga district and the Menchi Formation of the Gandis Mountains. From these beds, leaf impressions of Eucalyptus angusta, E. geinitzi, E. oblongifolia, Ficus daphnoycnoides, F. stepheuseni, F. myrtifolia, Cassia fayattensis, C. marshalensis, Celastrus minor, Quereus orbicularis, Rhamnus menshigensis, Juglandites sinutus, Phrynium tibeticum Cyperacites of. haydenii and Typha sp. were obtained. Of which the genus Eucalyptus appears to be predominant. The geological age of this flora is assigned to Upper Cretaceous-Paleogene. It indicates that during this time the flora is mainly composed of evergreen broad-leaved trees thriving under a hot and wet climate. Fossils obtained from the Ye-Ma-Gou Formation of Gandis Mountains mainly consist of Populus balsamoides, P. latior, P. glandulifera, Salix sp. and Leguminosites sp. The age of this flora is assigned to Miocene, the fossils indicate that by that time deciduous broad-leaved trees were flourishing in that area. The Miocene of the Wulong Formation consists of Quercus semicarpifotia, Q. pannosa, Q. senscens, Q. spathulata, and some species of Thuja, Sabiua, Spiraca, Carpinus, Betula and Rhododendron the flora is mainly composed of evergreen and deciduous broad-leaved trees and along with some conifers, and was thriving under a cooler and arid climate. This flora is quite different from the previous one which caused by the uplift of the Himalayas. The composition of this flora is very similar to the Neogene flora of Yunnan which indicates that at that time Xizang and Yunnan probable belong to the same floristic province. The discovery of Eucalyptus in Xizang shows that the climate of Xizang during Upper Cretaeeous-Paleogene was much warmer than that of Tibet at present. It also shows that this genus which now flourishes in Australia may originate from the northern hemisphere.

An attempt has been made in this paper to describe briefly the characteristics, ecological environments and the origin of the subnival vegetation of Xizang based on the information collected in the field. 1. This snbnival vegetation of Xizang is distributed in the subnival zone between the continual plant cover line and the permanent snow line on the alpine zone. The climate is severe. The vegetation is primitive, being composed mainly of some lower plant com- munities, mosses communities and some mesophytic flowering plant communities in spots. It is lower and sparse and can be classified into three major types, as follows: (1) Type of humid climate in the southern slopes of the eastern ttimalaya and Kangrigarbo rang. (2) Type of subhumid climate in the eastern Xizang. (3) Type of arid and semiarid climate in the central and western Xizang. 2. The mieroclimate plays a decisive role in the existence and development of the subniwfi vegetation. To the severe conditions, plants also wisely adapt, utilizing whatever water and heat available, completing their growth and development stages in a very short period, and resisting to cold and other unfavorable factors. 3. Frmn the analysis of the cmnposition of the flora of subnival vegetation in Xizang, it is shown that the subnival vegetation has evolved from alpine vegetation of Xizang and the neighbour region to eastern Xizang and southern Xizang.

Crotalaria juncea Linn. is an annual berbaceous plant of Crotalaria Linn. of the Leguminosae. It is widely used as green manure in our country, because its seed contaius 26.90% endosperm, of which more than 70% belong to galactomannan. Therfore it is also a kind of plant contained gum. The ratio between galactose and mannose is 1:2.3 in the galactomanuans. The seed gum of the Crotalaria juncea Li. in water will increase its solubility and viscosity as the temperature increases, but when the temperature is increasing over 70℃, it will cause the viscosity to decrease greatly. In the condition of alkaline medium, Crotalaria juncea Linn. seed gum solution with high viscosity can easily connect with borax to form gel. It is also used in the petroleum industry for having this good property. Crotalaria juncea Linn. seed gum may be a newsources for the hydraulic fracturing fluids of hydrogel.

The rate of photosynthesis in various types of wheat was ordered in descending scale as follows: wild type, spring, winter and local varieties. The increase amount in the rate of photosynthesis depended on the course of growth and develoment of the wheat plant itself. It reached maximum at flowering stage, there after, it decreased gradually. The curve of the rate of photosynthesis was unipeak type. 2. The rate of photosynthesis in wheat leaves was higher in upper leaves than the lower ones. It was raised to maximum in flag leaves. The rate of photosynthesis in flag leaves of 61 cultivars was 28.44 mg CO2/dm2 hr. in average, the range of variation was 19.97 to 32.66 mg CO2/dm2 hr. Difference of the rate of photosynthesis among varieties was significant. In 21 cultivars the rate of photosythesis was in average 8.11 mg CO2/dm2. hr. and the range of variation was in 5.0 to 14.0 mg CO2/dm2. hr. and significant difference occurred. 3. The light compensation point of flag leaves of wheat plant was about 700 Lux. At this time, with increasing light intensity the rate of photosynthesis raised too. The satura- tion point of light was about 50,000 Lux. The light intensity was further increased the rate of photosynthesis decreased. On the contrary it was found that the rate of photorespiration did not decreace. 4. In different years and under the different enviromental conditions, the rate of photosynthesis varied among different cultivars of wheat, but the order of that was basically the same. The differece was not significant.

The 14C-B9 was used by smearing the surface of the leaf of peanut plant (Arachis hypogeae L.) during the flowering stage and pegging stage. The results obtained with the measurement of radioactivity were as follows: The incorporation of B9 into peanut plant was very fast, and the radioactive isotope was so much accumulated in the leaf of the main stem one hour after treatment. Foul hours after treatment, B9 would also be occurred so much in the flower. After 3 days, the radioactive isotope was accumulated in the organs of peanut plant up to the maximum amount. In the pegging stage the translocation of B9 into the organs of peanut plant was faster than that in the flowering stape having the maximum amount of accumulation in the first day. The rate of out flow of B9 from the smearing leaf was high. It was shown that the radioactivity was mainly concentrated in the young tissues of stem and leaf, and in the flower and small pod. By using microautoradiography, the radioactivity was translocated through the vascular bundle in the petiole and stem of the peanut plant. Later, it was chiefly distributed in the cortex of the stem and the palisade tissues of the leaf. In the flower, the 14C-B9 was firstly found in the vascular bundle of the filament and the petal. After 3 days, the radioactive isotope was transported into the pollen grain and concentrated in the inner wall of the pollen sac. The chromatogram of the radioactive matter extracted from the peanut plant was showed that the compound of B9 was biochemically stable and degradated not easily in the peanut plant.

In this experiment, we have tried to make a comparison of analytical peroxidase isozyme of waxy maize from South China, using vertical polyacrylamide gel electrophoretic method. 70 cultivars (lines) of the waxy maize and other materials were examined. The main results were summarized as follows. 1. Eighteen of the nineteen waxy maize cultivars from the original region of "Menghai four-row Wax" showed the fifth band of peroxidase isozyme, and one showed mixed band having fourth and fifth band. 2 Among 15 tested waxy maize cultivars from Yunnan Sheng, eleven of them showed the fifth band of peroxidase isozyme, two showed the fourth band and two showed the mixed band. 3. Seventeen of the nineteen waxy maize cultivars from Guangxi Zhuangzu Zizhi- qu showed the fifth band and two showed the mixed band of peroxidase isozyme. Accordingly, conclusion might be drawn that the most (86.8%) of waxy maize cultivars from South China showed the fifth band of peroxidase isozymc. That is similar to Coix which is originated from China. On the contrary, the dent maize from America showed the fourth band. The experimental results further demonstrated that Chinese waxy maize (Zea mays ) might be originated in South China. China is not only one of maize secondary origin centre, but also might be one of primery origin centre of maize.

(1) The pollen grains of Pennisetum can germinate normally on the stigma of rice and the pollen tubes can grow into the style and enter the embryo sacs. However, the process of double fertilization is slow and more or less abnormal and phenomenon of simple fertilization often occurs. (2) It has been found that in the majority of cases the development of the embryos is slow and stays long in the stage of globular embryos, thus, the differentiation of the embryos is very difficult and degeneration of the embryos appears many times. Simple differentiation was observed only in some embryos during 16–24 days after pollination. Normal differenting and developing embryos were not observed. The cause of the degeneration of the embryos is related to the state of endosperm development and also to the non-coordination of the genomes of both parents. (3) The development of the endosperm is abnormal. The change from the free nuclei into the cells in the endosperm is delayed as late as the 8th day after pollination. The whole endosperm tissue is composed of the cell masses which are quite different both in shape and function, a part of these endospemn cells lacks the ability to synthesize starch. The disintegration of the endosperm could be frequently observed during their development. (4) A lots of starch are accumulated in the nucellar cells near the antipodals, It is shown that there was some metabolic confusion resulted from the crossing in the embryo sacs. Based on the above mentioued results the authers consider that the failure of producing seeds by crossing is at least related to the nutrient condition which are essential for the development of embryos. If embryo culture technique is employed at the early stage of the embryo development the hybrid seeds could be obtained.

A primary study on the process of Hyphae Digested of Gastrodia elata BI. has been made through cytological and idstoebemieal methods. 1. When the cortical ceils of Gastrodia elata corm had been infected by Armillaria mellea Fr., its vacuole disrupts and disappears in the protoplast, so that the hyphae were changed in nature and then hydrolyzed; The cells themselves too, were bydroiyzed at the same times. In our inference, this period of hydrolysis happens because of the function that the vacuole release the hydrolases. Thus, the cells and fungal hyphae have been changed in their form and histoehemisty. 2. During the changes of cortical cells of corm, the outer-most part of the columella parenchyma cells also changs greatly, such as the appearing of renewable nuclei, the changes of the form and the structures of nucleoli, the disappearing of polysaccharide particles, the increasing of the content of RNA, the increasing of mitochondrias in large quantity etc. All these changes show the active process of synthesis in the large cells.

Ultrastructural events in wheat sperm cell development were examined from the division of generative cell stage to the maturation of sperm cell in pollen grains. The results are smnmarized as follows: 1. The generative cell in forming microspore by mitosis goes through a series of changes including tile displacement and transformation. It finally becomes a spindle-shaped cell getting ready for another mitosis. The generative cell at this stage is naked. it is only surrounded by both membranes of its own and vegetative cell Most part of the generative cell is occupied by the conspicuous elliptical nucleus with highly condensed chromatin. With the exception of ribosomes, the organelles in the thin layer of generativc cell cytoplasm are obviously fewer and smaller than those in the vegetative cytoplasm. The mierotubules may also be seen in the cytoplasm of spindle-shaped generative cell parallel to the long axis of the cell. There is no amyloplast in generative cell. 2. When the generative cell has moved to the position close to the vegetative nucleus again, it begins to divide. The formation of sperm cells as the result of mitosis of generative cell, and the development of sperm cell involves the following main changes. The shape of the sperm cell tranforms from spherical to elliptical, finally it forms an elongated cell with a tail-like structure. At the sametime, the distribution of cytoplasm gradually concentrated at one end of the sperm cell to form the cytoplasmic extension, so that the so called "tail" of the sperm cell is formed. There are more organelles, especially the mitochondria, assembling in this part. The sperm cell just formed after mitosis is naked and the enclosed plasma membrane is discontinuous. The sperm cell membrane is enclosed by vegetative cell membrane, and the double membranes may be completed at a later stage. It is considered that the period which follows is very short, the deposition of wall material, the callose, occurs to fill up continuously the space between two membranes, but soon after this period the cell wall becomes discontinuous and the wall material is obviously decreased. The significance of the position of the generative cell before its mitosis and the morphological changes during the development of the sperm cell are discussed in this paper.

The tumor-like callus, obtained usually from the surface of explant of woody plant, may be originated from various parts, involving especially epidermis or hypodermis, distal from the cut surface of the explant. These experimental evidences may be used to support the conception of that exogenous hormones play an important role in the induction of callus. The developmental stages of establishment of the callus may be characterized by changes in cell morphology and metabolic condition of the tissue. During the induction or activation phase, a regressive change appears in the peripheral layers of the explant, involving a progress return to a meristematic state denoted by increasing nucleus and nucleolus size and accmnulation of RNA and results in the dedifferentiation of the cells. This is followed by a division stage with substantial accumulation of RNA and active cell division, thus, the peripheral tissue of the explant has been activated and become embryonic tissue and then, the division stage cannot be considered as the phase of regressive change or dedifferentiation. The formation of meristematic nodules in a common feature in developing callus culture and they are originated at random from solitary parenchymatons cells, which by means of dediffercntiation have become meristematic in character. The meristematic