20 S. SAGUCHI 



It will be seen from the above account that the b cells contain 

 the Golgi apparatus in the height of its development; in the a 

 cells it is in the earlier stage of its existence, while in the e cells 

 it is in the terminal stage. 



Pigment granules. Some of the islet cells contain yellowish- 

 brown pigment granules which are well preserved in sublimate or 

 in Rabl's mixture (fig. 22). They stain black by the Cajal 

 method (fig. 49), as is the case with the pigment in nerve cells. 

 They are present in two forms — small granules and relatively 

 large, somewhat spherical corpuscles, which when viewed in sub- 

 limate or Rabl preparations, consist of a cortex of pigment gran- 

 ules, and of a more faintly staining internal substance. In the 

 Cajal preparations, on the contrary, the whole of the corpuscle 

 takes a deeply brown color and its surface is furnished with 

 short, thorn-like prolongations which correspond to the row of 

 pigment granules found in ordinar}^ preparation. Although vary- 

 ing in number and intracj^toplasmic position, they are present 

 in the e cells, that is to say, in those which are laden with lipoid 

 corpuscles. In addition, the pigment content of the cells is sub- 

 jected to much variation according to the islet examined. 



MITOSIS AND AMITOSIS 



Bizzozero and Vassale ('87), Laguesse ('95-'96), Ssobolew 

 ('02), Lane ('07-'08), and others record that they have found 

 mitotic figures in islet cells. Laguesse ('09-'10), in addition, 

 describes that in man mitosis is rarely found in the islet, whereas 

 amitosis is not infrequently met with. In the cytological study 

 of the islet m}^ attention was repeatedly attracted to the presence 

 of karyokinetic figures in both b and e cells (figs. 56 to 58). Cells 

 with two nuclei are also found in the islet, the nuclei being situ- 

 ated either one upon another or side by side according to the 

 shape of the cell. It is my belief that they are produced, not by 

 mitosis, but by an amitotic fragmentation of the nucleus. Cases 

 are occasionally observed where a connection exists between the 

 two nuclei which may be regarded as being in the nature of a 

 constriction (fig. 59). On the other hand, the amitosis accom- 



