596 



MANUAL OF HISTOLOGY. 



^ A ?,Lv? ^'^ITl I*.* 



III 



0-025-0-040 mm. in diameter, 

 are met with at wide intervals. 

 These present roundish or oval 

 nuclei. Usually from the apex 

 of the cell one process passes 

 outwards, and three others 

 from the broader part inwards. 

 They may be seen to be of fibril- 

 lated structure. The middle 

 one of these basal processes is 

 in contrast to the others, which 

 ramify, an "axis-cylinder pro- 

 cess" (Meynert, Koschewnilcoff), 

 and is prolonged into one of 

 the nerve-fibres of the corona 

 radiata. (3.) The smaller cells 

 of the third layer are also said 

 to present the same arrange- 

 ment likewise. 



(5.) A layer of closely packed, 

 roundish, smaller cells 0*008- 

 0-010 mm. in diameter, with 

 hardly recognisable processes 



(i). " 



(6.) A lamina, consisting of 

 fusiform cellular elements, mea- 

 suring O'OSO, from whose apices 

 filiform processes spring (5). 



These last ramifications are 

 not supposed to have anything 

 to do with the corona radiata, 

 but are connected, in all pro- 

 bability, with " associating 

 fibres " of Meynert. The mul- 

 tipolar ganglion cells of the 

 fourth layer are stated by this 

 observer to be motor, the ele- 

 ments of the fifth resembling 

 the "granules of the retina" 

 (see below), possess sensitive 

 properties. This is all, in our 

 opinion, purely hypothetical. 



A discovery has recently 

 been made by Gerlach which 

 seems important. The cortex 

 of the cerebrum presents, 

 namely, in the first place, a 

 wide-meshed network of medul- 

 lated fibres in whose inter- 

 stices ganglion cells are situ- 

 ated. Here we find, besides 

 that very delicate network of 

 extremely fine fibres already 



