270 KIYOYASU MARUI 



forms they have striking resemblance to an amoeba. Besides the 

 typical forms I found many others which do not resemble amoeba. 



Before I pass to the description of the amoeboid glia cells, I will 

 pay some attention to the manifestations of glia cells which go 

 hand in hand with the appearance of the former. Although not 

 so numerous, we find glia cells in every stage of regressive and pro- 

 gressive change (figs. 9, 10, and 14). The regressive nuclei 

 appear sometimes extremely swollen and' pale and at other times 

 they show a zigzag shape and deep stain. The homogeneous 

 stain of the nucleus and protoplasm, the breaking up of the nu- 

 cleus into spherules or small masses are other histological prop- 

 erties of the regressive nuclei. Furthermore, I observed in the 

 same sections production of young amoeboid glia cell ; karyokinesis 

 of the glia nucleus was found now and then, and amitosis of the 

 nucleus, observable occasionally in the physiological condition, 

 seems to appear oftener in fatigue preparations (fig. 6). 



In young amoeboid glia cells the shape of the cell body is 

 simple and we find sharply marked protoplasm around the nu- 

 cleus. In older cells, however, the protoplasm grows larger and 

 sends processes of irregular shape in different directions. The 

 process itself has at first a simple shape, but later it shows a more 

 or less complicated shape; sometimes I observed that the glia 

 cells send the processes to nerve fibers or capillaries, holding the 

 latter between their ramifications. Generally speaking, the 

 amoeboid glia cells were found relatively more numerous near 

 the blood-vessels than in the other parts of the synapse. In 

 young amoeboid gl'a cells the protoplasm is first quite homogene- 

 ous, but in the further course of life many kinds of manifestation 

 become noticeable in the cell body. 



In the Mallory preparations (fig. 12) the protoplasm of large 

 amoeboid glia cells contains variously large vacuoles ; the size of 

 the vacuoles varies considerably, but generally speaking they are 

 not very large in my preparations. The number of the vacuoles 

 is also variable with the s'ze and age of the cell. The content of 

 the vacuoles is quite clear in my preparations; I assume that 

 these vacuoles are lipoid cysts, the content of which was extracted 

 in the process of embedding. In my thionin-eosin preparations 



