526 



NAOKI SUGITA 



pyramids. Next to the lam. gang., there is the lamina multi- 

 formis (VI) with polymorphous cells. 



In the sagittal section (fig. 2) the cortical area lying between 

 A A' and BB', — A A' marking the knee where the gray of the 

 olfactory bulb passes over to the frontal cerebral cortex and 

 BB' marking almost the middle of the parietal cortex covering 

 the lateral ventricle, — is distinctly provided with all the five 

 cell layers (fig. 3). The lam. zon., the lam. pyr., and the lam. 

 gang, are all typically constructed. In the lam. gran, int., espe- 







I. Lamina zonalis. 



I III. Lamina pyramidalis. 



1 IV. Lamina granulans interna. 



v. Lamina ganglionaris. 



Ectal sublayer' 



Ental sublayer J 



Lamina multiformis. 



Fig. 3 Diagram of the typical cerebral cortex of the albino rat, for illustration 

 of figures 2, 4 and 6. 



cially in material fixed in formol, the tissue surrounding the 

 granules may stain deeply, giving by low-power magnification 

 the appearance of a distinctly stained band, but this appearance 

 is not so evident in the material fixed in Bouin's fluid. The lam. 

 gran. int. may be distinguished from the lam. pyr. by the fact 

 that in the former the cells are small and crowded densely. 

 There is a narrow band poor in cells, between the lam. gran. int. 

 and the succeeding lam. gang. The lam. mult., in the albino 

 rat, is distinctly separated into two sublayers by a narrow, light 

 band very poor in cells. The broader (ectal) sublayer which 

 lies immediately below the lam. gang, is rich in cells, about equal 



