450 



THE INTERNAL STRUCTURE 



division is to be taken as implying that there is any 

 difference in kind between these pyramidal elements, 

 although they differ so much in size in different situations. 

 To speak of the largest of these cells only, viz., those of 

 the fourth layer as ' ganglionic ' cells, and of this layer in 

 particular as ' the ganglionic layer,' 

 carries with it misleading implica- 

 tions. Even the largest of the 

 clustered cells differs only in degree 

 from similarly- shaped cells found in 

 the layer above, and also in the same 

 layer throughout those other portions 

 of the cortex which do not possess 

 these cells in ' nests ' or clusters. 



The most consistent conclusion to 

 be drawn from these facts, by those 

 who adopt Ferrier's views, would be 

 for them to say that all convolutions 

 -Section of the coutaiu ' motor cells ' —and that too 

 in more than one layer — unless the 



' grouping ' 



Fio. lei 



Involuted Layer of the Hip- 

 pocai ipus (or Cornu Am- 



mopis). A, White fibres, niero fact of the nest-like 



wjiicli here, owing to absence in • • • 



of spindle and small cell of the cclls lu Certain situatious IS to 



'ayers, attach themselves im 

 mediately to C, the pyrt- 

 midal cells equivalent to tiie 

 iniier half of the third layer 

 of the five-laniinated cortex ; 

 r, 'stratum radiatum,' corre- 

 sponding to outer hdf uf 

 third layer ; m, I, equiva- 

 lents of the first and second 

 layers. 



be taken as an indication that such 

 cells have assumed ' motor functions,' 

 and are on that account to be desig- 

 nated as ' ganglionic' Either of 

 these positions would, however, pro- 

 bably seem to the ordinary reader to 

 be very poorly based on anything 

 like reasonable considerations. 



It is worthy of note that in the involuted grey layer of 

 the ' Hippocampus major,' the structure of the cortical 

 matter, as Meynert points out,* is extremely simplified, 

 * Strieker's " Human cand Comp. Histology," vol. ii. p. 395. 



