Chick embryos received a single injection of actinomycin D($0.1{\mu}g,\;0.05{\mu}g\;or\;0.1{\mu}g$) or puromycin($10.0{\mu}g,\;30.0{\mu}g\;or\;50.0{\mu}g$) into the yolk sac of Arbor acres chick embryos either prior to incubation or at certain periods of time (48, 96 and 144 hours) after incubation. After 10days of incubation, surviving embryos were investigated morphologically and biochemically. Embryos treated with actinomycin D or puromycin showed a high mortality when they were exposed prior to incubation and at 48 hours after incubation. Electron micrographs of chondrocytes in tarso-metatarsal of antibiotics (actinomycin D or puromycin) treated embryos showed the destruction of cytoplasm and nuclei when they were exposed prior to incubation. Endoplasmic reticulum was expanded and mitochondria were damaged in chondrocytes of surving embryos treated with low doses at 48 hours, 96 hours or 144 hours after incubation. The activities of enzymes such as lactate dehydrogenase, malate dehydrogenase and succinate dehydrogenase in embryos treated with actinomycin D or puromycin were much less than those of the saline treated group. Also, the amounts of DNA, RNA and protein were greatly decreased.

The endosperm cells and the umbiliform layer of ginseng (Panax ginseng C.A. Meyer) seed are studied with light and electron microscope. Differentiated mitochondria, ER cisternae, proplastids and ribosomes are characteristically observed in the endosperm cells of matured seed. The cell inclusions contain the protein bodies and the spherosomes. Protein body contains, in proteinaceous matrix, globoids and crystalloids. Particularly the crystalloids have the lattice structure, and the formation of globoids is closely related with ER. Umbiliform layer has the positive reaction on alcian blue (pH 2.5) and the metachromasis on the toluidine blue. The umbiliform layer is formed by autolysis of endosperm cells, and composed of the deformated cell wall and the lipoprotein bodies. Particularly a part of the lipoprotein body and the fibrilar network structure have the positive reaction on acid phosphatase.

난소절제한 흰쥐에서 $17{\beta}$-estradiol과 progesterone을 장기간 주사햐여 자궁상피의 형태적 변화를 전자현미경으로 관찰하였다. 난소절제 후 자궁상피는 막성구조물과 지방구 기타의 구조물을 포함하는 vacuole의 출현이 특이적으로 나타났다. 상피는 낮은 입방형이며 세포 유리면에 소수의 짧은 microvilli를 볼 수 있었다. Estradiol투여시 상피는 높은 윈주형을 나타내며, 분비계는 비교적 잘 발달되고, 세포 유리면에 소수의 긴 microvilli도 관찰되었다. Progesterone 처리시의 상피는 세포 첨단부에 다수의 vacuole과 핵하부에 다수의 지방구의 집적이 관찰되었다. 이상의 결과로 보아 자궁상피는 형태학적 및 기능적인 상태에서 estrogen과 Progesterone 양자에 의해 변화를 받으며 이들 호르몬은 상피세포에 대해 독특한 영향을 나타낸다고 생각된다.

Fine structure of dormant and swollen conidiospore from Trichoderma koningii and the mechanism of protoplasting from the conidiospore were studied by scanning and transmission electron microscopy. The cell wall of dormant conidiospore was two-layered structure which consisted of electron dense outer layer and electron transparent inner layer. After 8.5 hrs incubation. the conidiospore was swollen and the outer layer of cell wall shown unequal thickness and partial breakage. Protoplast was released through the pore which has been formed by the breakage of outer layer and dissolution of newly synthesized cell wall for germ-tube formation. Swollen conidiospore and protoplast in releasing process contained various cell organelles and vacuoles with electron dense materials. The protoplast contained looser cytoplasm and had no cell wall materials outside of plasmamembrane.

The ultrastructure of the pars distalis of the adenohypophysis was studied in the female Korean native goat ($10{\sim}16kg$, B.W.) by electron microscopy. Six granular cells and one agranular cell were recognized according to the characteristic patterns of secretory granules and cell organelles. Type I cells were. large, round or oval and contained the largest granules of 290 to 490 nm in diameter, Their endoplasmic reticula were well developed and packed with parallel lamellae close to nuclear membrane. Type II cells were elongate or polygonal. They contained granules of 220 to 390 nm in diameter and well developed Golgi complex. Type III cells were round, oval or angular and contained granules of 150 to 300 nm in diameter. Their endoplasmic reticula were coarsely scattered among the granules and provided an intracellular compartment for segregation in groups. Type IV cells were oval or round and contained granules of 120 to 280 nm in diameter. Their endoplasmic reticula were arranged at one pole of cytoplasm. Type V cells were round or polygonal and contained small granules of 110 to 140 nm in diameter Their endoplasmic reticula were packed with regularly parallel lamellae. Type VI cells were stellate and irregular in shape and had cytoplasmic processes projecting between the neighboring cells. Their granules were less than 130 nm in diameter, the smallest among the cells of the pars distalis. Agranular cells had no granules or a few, if any. They were stellate or irregular in shape.

The organic phosphorus compounds have been widely used as an insecticide, since toxicity of these compounds is especially drastic to the insects than to men and other mammals. The organic phosphates are rapidly hydrolized and hence have little cumulative and ecologic effects. However, due to their acute toxic effects organophosphate have recorded rather high fatalities in men and domestic animals. The organic phosphorus compounds are powerful inhibitors to the carboxylic esterase enzymes such as acetylcholinesterase and pseudocholinesterase. As a result of firm binding characteristics of phosphate radicals to the active sites of enzyme, the activities of these enzymes are inhibited by the organophosphates. The organophosphates such as diazinon is easily observed from skin, gastrointestinal tract, conjunctivas and respiratory tract, and it is converted to more toxic form during metabolism in the liver The present study was carried out in order to investigate the hepatotoxicity of diazinon by observing the changes in the ultrastructure of cytoplasmic organelles of hepatic cells in albino mice. The animals were killed at 6, 12 and 24 hours after administration of 25mg/kg diazinon. The piece of hepatic tissue obtained from each animal was ultrathinly sectioned. The specimens stained by uranyl acetate and lead citrate double contrast methods were observed with JEM model 100B electron microscope. The results obtained were as follows: 1) A prominent dilatation and sacculation of the cisternae of rough endoplasmic reticulum associated with detachment of membrane bound-ribosomes, and disaggregation of the free ribosomes were recognized. 2) The hypertrophy of the smooth endoplasmic reticulum associated with depletion of the glycogen particles was observed. 3) The atrophy of cisternae of Golgi complex was observed. 4) A large number of secondary lysosomes (autophagic vacuoles and residual bodies) were formed. Consequently it is suggested that diazinon would induce disorganization of the cytoplasmic organelles of hepatocytes in albino mice.

Structural differences in various divisions of the rabbit colon were investigated using light and scanning electron microscopy. For light microscopic study, various Portions of the colon from seven rabbits (2.5 kg body weight) were fixed in 10% neutral buffered formalin, and paraffin sections were stained with hematoxylin-eosin. Tissues for scanning electron microscopy were fixed in 1% glutaraldehyde-1.5% paraformaldehyde and postfixed in 1% $OsO_4$, dehydrated to 100% alcohol, transfered to isoamilacetate and dried by the critical point method. Subsequently, specimens were coated with gold and viewed with a JSM-35C scanning electron microscope. The colon displays a morphological diversity along its proximo-distal axis. Five regions can be discerned based on the macroscopic and microscopic characteristics. 1) The first segment immediately distal to the cecocolical junction possessing three teniae is approximately 5 cm ($4{\sim}6cm$) in length, and displays irregular folds of the mucosa oriented transversely similar to those of the cecum. 2) The second segment possessing three teniae is about 7 cm ($5{\sim}8cm$) in length, and is characterized by the papilla-like protrusions on the mucosal surface. 3) The third segment, possessing a single tenia is about 16 cm ($12{\sim}20cm$) in length, and also displays the papilla-like protrusions similar to the aforegoing segment. 4) Fusus coli, approximately 4 cm ($3{\sim}5cm$) in length, is free of teniae and exhibits longitudinal folds on the mucosal surface. These four portions together constitute the proximal colon. 5) The distal colon reaches a length of about 58 cm ($53{\sim}55cm$) and shows a pattern of surface irregularities with minor ridges on the mucosal folds.