152 Journal of Comparative Neurology. 



extravascular leucocytes in salamander multiplication is by 

 mitosis or nucleary cell-division. Lowit attempted to distin- 

 guish between erythroblastic and leucoblastic nuclei and claimed 

 that mitosis occurs only in the erythroblasts, which are devoid 

 of amoeboid movements. Flemming, however, finds that mito- 

 sis is common in the amoeboid leucoblasts and thus agrees with 

 Miiller, Bezzozero and Newmann. The author thinks it proba- 

 ble that fragmentating cells (i. e. amitotic elements) are in a 

 state of decline and are incapable of reproduction. This may 

 be compared with Frenzel's view that the cells reproducing by 

 fragmentation are substituting and not constructive elements, as 

 in the case of those cells in the mucous membrane which are to 

 degenerate in the formation the mucous secretion. The nature 

 of leucocyte proliferation in the brain should have careful study 

 with modern methods. 



In the layer of large pyramids the degenerative process is 

 more conspicuous by reason of the larger size of the elements 

 but no more general or relatively extensive. In the radial fibres 

 we encounter here and there a phenomenon of which we 

 find no mention elsewhere. Long deeply staining nuclei, resem- 

 bling in color the leucocyte or "granule" nuclei, but many times 

 as long as wide lie in the course of the fibre and seem to occupy 

 the sheath. This is probably different from the varicose condi- 

 tion of the apex process sometimes encountered, Figs. 4, 5, 

 Plate B. These bodies at times very closely resemble the nuclei 

 of the intima of the vessels and must be carefully distinguished 

 from these nuclei when greatly elongated in the finest capillar- 

 ies. The color and appearance and the small diameter as well 

 as the position of these bodies serve to prevent error. We in- 

 cline to believe them characteristie of the degenerative condition 

 as stated more in detail below. 



The innermost cortical layer, that containing multipolar 

 cells, offers no noteworthy peculiarity. 



A typical motor region is found in No. 2, from the pre- 

 central or ascending frontal convolution. Here the nests of 

 very large pyramids with long processes are eminently charac- 

 teristic. Fig. 13 of Plate B. gives a good idea of these cells 



