260 KIYOYASU MARUI 



structure and consist of endothelium and adventitia with very 

 few nuclei. As already remarked, the adventitia of the capillary 

 is connected with the bases of the reticular beams; but I was not 

 able to distinguish the perivascular limiting membrane of Held as 

 a membrane separated from the adventitia, so that I could not 

 find the so-called perivascular lymph space between them in 

 normal fish brains. 



THE HISTOLOGICAL ^MANIFESTATIONS OF THE MAUTHNER CELL 



IN FATIGUE 



To recapitulate and discuss the results of other authors here 

 would go beyond the purpose of the present work; my remarks 

 will be restricted to my main results of investigation. 



The cell body of fatigued cells was found either in the state of 

 turgescence (figs. 3 and 4) or of shrinkage (fig. 5) ; in the former 

 case the cell border was convex between the dendrites and the den- 

 drites appeared shorter, whereas in the latter the cell border was 

 concave and the dendrites looked longer. I agree with the opin- 

 ion of Vas (33), Mann (23), Lugaro (21), Pugnat (26) and Holm- 

 gren (17), that the enlargement ^f the cell body is to be considered 

 as the manifestation of activity and the shrinkage as that of ex- 

 haustion. In this way the results of Hodge (14, 15, 16), which de- 

 viate from those of others, might well be interpreted. Dolley (7, 

 9) described the fluctuations of the size of the cell body in the 

 course of activity, but I have a little doubt about his statement 

 that in later stages the absolute size of the cell body increases 

 steadily to the end. The alteration of the Nissl substance mani- 

 fested itself in more or less advanced stages of chromatolysis, as 

 was described by Vas (33), Lambert (20), Mann (23), Lugaro (21, 

 22), and many others, and thereby the cytoplasm was stained vari- 

 ously deeply (figs. 3, 5). The Nissl bodies were found in a state 

 of fragmentation, shortening, and irregular distribution; in the 

 advanced stage of chromatolysis they were reduced to fine gran- 

 ules or even to a homogeneous substance. Sometimes I observed 

 the central beginning of the chromatolysis, as was stated by Vas 

 (33), Mann (23), and, in tetanus, by Sjoeval (32). 



