宽口虫(Steinia sp.)无性生殖周期中核器和纤毛器的演化

利用改进的蛋白银染色法，研究了宽四虫（Steiiniasp．）的形态及其无性生殖周期中核器和纤毛器的发育演化过程。其发生过程为：1．大核改组带出现后，口原基出现在老口围带后方之腹棘毛左侧，其内的毛基体组装成整齐排列的小膜，构成新AZM，老AZM后部也发生部分更新的现象。2．颇腹根棘毛原基各5列，分别以3：3。3：4：3方式分化成前、后仔虫的额、腹、横棘毛。3．在第1－3列背触毛中，分别于前、后仔虫的中部范围产生第1—3列新原基，每列原基向两端伸展替代老背触毛列，成为前、后仔虫相应的第一列新背触毛。4．在前后第3列背触毛原基后端发生前、后第4列原基，它稍偏向第3列原基的右侧，向前伸展成第4列背触毛；在虫体腹面，前、后右缘棘毛原基的前方出现第5、6列背触毛原基，后发育为第5、6列背触毛，在虫体演化过程中转位到背面。

EVOLUTION OF NUCLEAR APPARATUS AND CILIATURES OF STEINIA SP. DURING ASEXUAL REPRODUCING CYCLE

Using protargol technique the morphogenesis of the soil ciliate,Steinia sp. during its asexual reproducing cycle has been studied. The main process is:1) after the appearance of macronuclear reorganization bands, the oral primordium is formed between AZM and ventral Cirri. The kinetosomes in this area assemble into many pieces of neatly arranged membranelles and subsequently the new AZM is formed;2) anlagen of undulating membranes and that of cirri are formed after the disintegration of frontal and ventral cirri. The differentiation, migration and location of ciliary organelles take place afterwards; 3) within the left 3 dorsal kineties (DK),three new DK-anlagen in both proter and opisthe origin and develop in the middlepart of the old structure. Each row extends forward and backward and takes theplace of the old bristle rows. Finally, they form the corresponding lst-3rd dorsal ciliary row, then 4) the 4th anlage seems to be derived from the rear end of the 3rd DK-row, which extends forward afterwards. The 5th and 6th row of dorsal kineties in both daughter cells develops up-right in front of the anlagen of corresponding right marginal cirri usually located on the ventral side of the organism.