120 Dr. E. Schuster. Cell Lamination of the [Sept. 30',. 



The cells are some of them irregular pyramids slightly larger than in that 

 layer, while others are smaller cells of the granule type. The latter are to- 

 be met with also in the deeper layers, but are more numerous here. 



4. Layer of large pyramids about 0*4 mm. in breadth. 



The cells are much the same as those of the corresponding portion of 

 Type II ; they lie 0'4 mm. farther from the surface. 



5. Layer of polymorphic cells. This is about three-quarters of the breadth: 

 of the corresponding layer in Type II, measuring 0'45 mm. across. The- 

 constituent cells of both types appear to be much the same in structure. 



Distribution. — This type of cortex covers the greater part of tlie lateral 

 surface of the hemisphere. Above it changes more or less suddenly into 

 Type II ; below and behind the fissura postsylvia anterior {fpsa) forms its 

 boundary, while in front it extends almost as far as the fissura rhinica 

 anterior (frha). It is separated from the upper lip of that fissure by a 

 narrow strip of cortex of simple structure, rather resembling Type I 

 Type III varies somewhat in its details in different parts of the wide area 

 which it covers. It is narrower on the walls of the fissures, the cells are less 

 numerous and are shorter and broader. 



Type IV. ® © © CD {vide fig 5). 

 Tlie depth of cortex is about 1"8 mm. The following layers may be 

 distinguished : — 



1. Molecular layer, 0*2 mm. deep. 



2. Dense layer of cells of various shapes, measuiing 15 to 30 fju in length. 

 There are some pyramidal, giving off one process towards the surface, while 

 others are inverted pyramids giving off two or more processes in that 

 direction ; others again are stellate or fusiform. This layer stretclies to a 

 depth of 0-5 mm. In its deeper portion, the cells are less crowded, and a 

 number of granules are present. 



3. A distinct layer of granules, O'S mm. in width, which stretches to 

 a dejith of 0-8 mm. The exact shape of the granules was diflicult to 

 determine owing to bad preservation. Among them are larger cells of 

 pyraiiiidal or irregular shape. 



4. A layer of large pyramids and polymorphic cells, of which many are 

 30 to 35 fi in length. Among them are smaller cells of the same shapes and 

 scattered graimles. 'J'his layer has no very definite boundary, but its 

 constituents get smaller at a deptii of al)()ut I I iniu. 



Tyi'K V. OOOO {<^^de tig. G). 

 1. The molecular layer is very broad, strelchiug downwards to depth of 

 0'4 mm. below the surface. 



