CYTO LOGICAL STUDIES OF LANGERHANS's ISLETS 19 



1) There are found irregularly spherical or elliptical corpuscles of 

 various sizes, which consist of a deeply staining cortex and a pale 

 main mass (figs. 35, 36). These corpuscles are often connected 

 with one another by threads of varying thickness which show 

 the same staining reaction as the corpuscles (fig. 37). From the 

 shape and position on the one hand and from the absence of lipoid 

 corpuscles on the other, it is probable that the cells which con- 

 tain these bodies belong not to the d or e type, but to the granu- 

 lar type of cell, especially to the a and h types. 2) There are 

 typical nets which are formed by the anastomosis of thin or thick, 

 often double-contoured threads (figs. 38, 39, 42). These are situ- 

 ated either between the nucleus and an extremity of the cell or 

 along the side of the nucleus; in the latter case, the net is flat- 

 tened and elongated (fig. 42). 3) Another form of Golgi's ap- 

 paratus is represented by rings or loops (figs. 40, 43, 44). The 

 ring (usually there is only one) is generally situated near the 

 nucleus. There are also cases in which the ring or loop emits 

 various prolongations which either anastomose with one another, 

 end freely in the surrounding protoplasm, or run along the side 

 of the nucleus toward the other end of the cell. 4) The appara- 

 tus sometimes appears as threads (fig. 21), which may be straight 

 or curved, situated near one end of the cell, or alongside of the 

 nucleus. The latter three forms of the Golgi's apparatus are 

 found in cells with lipoid corpuscles. The lipoid content of 

 these cells, however, is small; therefore they must be looked upon 

 as belonging not to the e type, but to the h type. Most of the 

 e cells, which contain a large amount of lipoid substance, are 

 devoid of the apparatus in question (fig. 41). There are also 

 other forms which may be regarded as transitional between the 

 types mentioned above. I am of the opinion that these grada- 

 tions point to a course of development and of involution of the 

 structure. In fact, it is not difficult to see how the corpuscles 

 become elongated and connected with one another (fig. 37) in 

 order to form the typical net. On the other hand, the net under- 

 goes regressive metamorphosis by a gradual thinning and ad- 

 herence of the trabeculae or threads, so that, at last, it leads to 

 the formation of a single ring or loop, or even a delicate filament 

 w^hich gradually disappears (fig. 21). 



