Sporo-pollen assemblages, with proteaceous pollen and Normapolles, are obtained from the boring cores and some black clay deposits in the vicinity of Er-Lian-Hao-Te city of northern Nei Monggol (Inner-Mongolia). Seventy species are reported, in which Proteacidites microverrucatus, Beaupreaidites striatus, Triatriapollenites echina- tus and Echitriporites magnus, are described as new. These assemblages are conspicuously poor in pteridophytes and rich in gymnosperms of the families and genera: Pinaceae, Podocarpaceae and Ephedraceae, especially Cedripites, Podocarpidites and Ephedripites. Angiosperms are quite diverse in types, besides the proteaceous pollen and Normapolles (Altantopollis, Pseudoatlantopollis cf. simulatus, Choanopollenites), Momipites coryloides, Momipites tenuipolus, Paraal- nipollenites confusus, Platycarga, Ulmoideipites tricostatus, U. krempii, Cranwellia cf rumseyensis, Disyllabipollis labeosus, Rhoipites, Lonicerapollis gallwitzi, L. scabratus etc. These pollen assemblages are assigned to the families Myricaceae, Juglandaceae, Betulaceae, Fagaceae, Ulmaceae, Proteaceae, Lorathaceae, Anacordiaceae, Symplocaceae, Aquifoliaceae and others. Most of them are tropical and subtropical. This indicates; that a warm-temperate and dry climate was prevailing at that time. Based upon the nature of sporo-pollen assemblages, the age of the black clay deposits is assigned to Maastrichtian. Maastrichtian pollen flora of northern Nei Monggol is associated with Siberian- Pacific Province by the abundanee of proteaceous pollen on one side and with the Euro-American Province by the presence of Normapolles on the other.

Vegetation of the Nei Monggol (Inner Mongolia) Autonomous Region can be classified into the following four major natural vegetational regions: Eurasia Coniferous Forest Region, East Asia Broad-Leaf Forest Region, Eurasia Steppe Region and Asia-Africa Desert Region. As a result of the differences in the temperature caused by the latitudes and in the precipitation by the southeast monsoon, five zones of vegetation may be distinguished in this region: the bright coniferous forest zone of cold-temperate type, the deciduous broad-leaf forest zone of mid-temperate type, the steppe zone of mid-temperate type, the steppe zone of warm-temperate type and the desert zone of warm- temperate type. Each of them has its own representative of vegetation formation and soil type, with corresponding climatic index. These characteristics have important bearing on the development of agriculture and animal-husbandry in this region. The vegetation of steppe and desert in this region is more arid than the Kazakstan steppe and Middle Asia desert. It is shown by the higher xerophilizaticn of edifieators and the lower productivity of communities. Difference of the characteristics of soil caused by different characteristics of vegetation may also be noticed.

The physiological activity of diBcAMP by various classical bioassay methods of cytokinin was studied. It exhibits the cytokinin-like activity in many ways of biological response, such as: the unfolding of etiolated barley leaf, the expansion of radish cotyledon, the expansion and greening of cucumber cotyledon and the inhibition of the elongation of mung-bean hypocotyl, etc. The activity of 1 mM diBcAMP was approximately the same as the activity of 0.044 mM benzyladenine in the most of the tests. However, the activity of 1 mM diBcAMP was found to be higher than the optimal concentration (0.044 mM) of benzyledenine in the radish cotyledon under the expansion test. There was no toxicity of diBcAMP in all of the bioassay methods used, even with higher concentration.

A stuty has been made of the chromosome number of root-tip cells and the chro- mosome configuration of PMCs in five intermediate forms of progeny of Triticum aestivum × Agropyron glaucum. The somatic cells in each of these intermediate forms have 28 pairs of chromosomes (2n=56) and the PMCs at diakinesis or metaphase Ⅰ of meiosis have 28 bivalents. The process of meiosis in most PMCs is regular. Lagging chromosomes and fragments at anaphase Ⅰ or telophase Ⅰ were observed only in few PWCs. According to our results, all the five intermediate forms of progeny of T. aestivum × Ag. glaucum are allooctoploids. The application of these allooctoploids is also briefly discussed.

After exposing etiolated wheat seedlings to intermittent light (cycle of 2 min. light, 118 min. dark) for 24 hr., we obtained an incompletely developed chloroplast membrane. It was then compared with a completely developed chloroplast membrane obtaining from wheat seedlings grown under normal light-dark regime. We investgated the effect of various cations and their concentrations on the absorption spectrum and the photosystem Ⅱ function of the above two types of chloroplast membranes. A similar effect of potassium and magnesium ions on the absorption spectra of completely developed chloroplast membrane was observed. They decreased the absorption peak values at both the red and blue regions of the chloroplast membrane in the same manner. The degree of decrease in the peak value is proportional to ion concentration. But in the incompletely developed chloroplast membranes similar phenomenon was not observed. In the presence of K+ and Mg2+ of various concentrations, the absorptionn peaks at the red region overlapped almost completely, and these at the blue region only changed slightly with ion concentrations. DCIP photoreduction rate of the two types of chloroplast membranes was stimulated by the addition of K+ and Mg2+ in various concentrations. But the degree of stimulation in the two types of membranes was quite different. In the presence of l00 mM KCl or 5.0 mM MgCl2, DCIP photoreduction rate of completely developed chloroplast membranes was enhanced by 76.8% and 68.9% respectively, whereas in incompletely developed chloroplast membranes it was only increased by 56.3% and 36.4% respectively. The causes of the effects of cations on the absorption spectrum and the photosystem Ⅱ function of two types of chloroplast membranes were discussed.

cordata Thunb growing in Guangdong province. The chemical constituents of the essential oil from this plant were examined by means of gas-liquid chromatography-mass spectrometric technique combined with systematic separation and thin layer chromatography. As a result of the analyses, ten components were identified: four monoterpenes-α-pinene, camphene, myrcene and d-limonene; two oxygenated monoterpenes-linalool and bornyl acetate; one sesquiterpene-caryophyllene and three aldehydeketone compounds-2-undecanone, decanoyl acetaldehyde and dodecanaldehyde. The results indicate that the composition of the essential oil from Houttuynia cordata growing in China is apparently different from that in Japan.

The leaf-blight bacteria (Xanthomonas oryzae Dawson) infect the leaves of the rice plant repeatedly, through the water pores at the forepart of the leaf blade. As the hydathode on top of the rice leaf-blade is not so conspicuous as that in the dicotyledons, such as Brassica, there is no reduced stoma on the summit of the leaf. However, many deformed stomata distributing irregularly at the forepart of the leaf are referred as water pores. These water pores being somewhat larger than the normal stomata are located very closely to the top and they become round by lateral bulging out. Besides, there are a few which are smaller than the stomata. After artificial inoculation by spraying with bacteria suspensions, the leaf-blight bacteria following the entrance through the water pores invaded the tracheids and spread over the veins and veinlets including the transverse veinlets connected between them. This kind of vein system facilitates the spreading of germs. At times the bac- teria may lodge in the immature tracheids or other parenchymatous cells. The development of disease with puncture inoculation was more rapid than that with spray inoculation. By way of puncture inoculation, it might or might not prick through the veins or veinlets, however, the course of proliferation in the vessels of various sizes of viens was basically similar to that of the spray inoculation.

Chloroplast FDPase was purified from spinach leaves by ammonium sulfate precipitation, Sephadex G-100 chromatography and DEAE-cellulose chromatography. It was found that treatment of the spinach leaves with liquid nitrogen prior to homoge- nization facilitated the subsequent isolation process, the optimal pH for FDPase activity was 8 to 9 and the enzyme was most stable at pH 6, under which it could be stored over several months without appreciable loss of activity. Acrylamide disc electrophoresis of the final enzyme fraction showed only one essential band. The two forms of FDPase, purified spinach chloroplast FDPase and that in fresilly ruptured spinach chloroplast, behaved differently in some of their kinetic properties. Their activities depended throughout on the concentration of Mg++, but the Km (Mg++) were quite different. The Km (Mg++) of the purified enzyme was about 6.0 mM, that of FDPase in freshly ruptured chloroplasts was, however, 1.0 mM, which corresponded to the concentration of Mg+* in the stroma of illuminated chloroplasts. Mg++ concentration was a limiting factor for the activity of purified FDPase. As the amount of Mg++ in the reaction mixture was lowered, the Km and Vmax were both greatly changed. The shortage of Mg++ could not be compensated by increasing the substrate concentration. The purified FDPase was completely inhibited by 15 μ moles EDTA in the teaction mixture, whereas the FDPase in freshly ruptured chloroplasts was inhibited only 70% by 30 to 45 μ moles EDTA, which was 2 to 3 fold of the concentration sufficient to inhibit completely the activity of the purified enzyme. Moreover, the former was more stable. Its activity did not decline even after incubation for over two hours The FDPase activity was higher in chloroplasts ruptured in 0.2% (w/v) Triton X-100 than that ruptured in water. This phenomenon suggests that this enzyme in vivo might be in some way associated, at least partly; with chloroplast lamellae.

After the calli derived from Olea europaea stem tissue have been introduced to the subculture on the solid medium for differentiation, a periderm was partially formed from the wound cambium in the outer region of the callus. At the same time, some scattered tracheids and vascular bundles were differentiated in the inside of the callus. These vascular bundles did not form a vascular system and also had no rela- tion to the organogenesis. In addition, there were some embryonic cells induced at random from parenchymatous cells in the callus, and these embryonic cells were characterized as the meristematic cells. Two types of meristematic tissues, namely, meristematic cellular mass and meristematic nodule, were produced by different types of mitotic division respectively. The meristematic nodules formed a growth center without any differentiation, but later, they were differentiated tracheids in the inner surrounded by the cambium-like cells. With monopolarity the root primordia were produced from this type of nodules. But the adventitious buds were derived from the meristematic cellular masses. Therefore, realize that the process of differentiation and dedifferentiation all occurs in the callus tissue. The structural differences among the nodules with tracheids, and the origin of buds and root primordia are also briefly discussed.

The present study of the formation of the generative and vegetative cells in wheat has demonstrated some cytological details at the ultrastructural level. The phragmoplast formed in telophase of the first microsporic mitosis extended centrifugally until it connected with the intine of the pollen grain. A new cell wall was then formed to separate the generative and the vegetative cells. By unequal cytokinesis the former is small and the latter large. In early developmental stage of male gametophyte, the organelles in the cytoplasm of the generaVive cell and the vegetative cells are similar, including mitochondria, dictyosomes, rough endoplasmic retieulum, free and clustered ribosomes and plastids, but microtubules were observed only in the early cytokinesis stage. In the further developmental stage of the male gemetophyte, the generative cell gradually detached from the intine of pollen grain and grew inward to the cytoplasm of the vegetation cell. When the generative cell became round and free in the cytoplasm of the vegetative cell, the wall materials between plasma membranes of the cytoplasm of the generative and the vegetative cells disappeared completely, so that it was a naked cell with a double-layer membrane at this time. The heterogeneity between both cells was then very conspiceous. The organelles in the cytoplasm of the generative cell have hardly any changed besides the degeneration of plastids, but in vegetative cytoplasm the mitochondria and plastids increased dramatically both in number and size. The rapid deposition of starch in the plastids of the cytoplasm of the vegetative cell made the most conspicuous feature of the vegetative cell in mature pollen grain. The significance of the presence of a temporary cell wall in generative cell and heterogeneity between generative and vegetative cells are discussed.

The Tertiary relic genus Catalpa, containing 11 Old and New World species, has multiple nectaries in the junctions of the major veins on the lower leaf surfaces. The generalized structure of the nectaries consists of a single, basal cell, and a single row of vertically oriented secretory cells. The nectaries are small, and contain no vascular tissue. Glandular and nonglandular trichomes are also present on the leaves. The glandular trichomes are structurally very similar to the nectaries, and probably are their precursors. Development of multiple nectaries in the lower leaf surface vein axils is considered to be an advanced strategy for attracting beneficial insects to control or minimize the effects of herbivorous insects. Chinese and American species of Catalpa are closely related, and have greater numbers of nectaries in more locations on the lower leaf surface than west Indian species. Herbivory pressures in the West Indies are postulated to be lower than on the continents, i.e. Asia and North America.

This is a continuation of two other papers. Eight new species are described, i.e.: Ctenozamites digitata, C. hongniensis, C. plicata, Ctenis pterophylloides, Pseudoctenis bifurcata, P. pachyphylla, Taeniopteris multiplicata and Lesleya triassica. The last genus is known only from Paleozoic of Europe, but it existed in the Mesozoic.