Edinger, TJie Significance of the Cortex. 73 



lobe, which is reduced to a mere membrane. The incision on 

 the right side passes laterad of the capsule leaving the thalamus 

 ganglia and opticus intact, while on the left side the genicula- 

 lum externum, optic nerve, the gangalon of the lattice layer, 

 and a part of the ventral thalamus nidulus were also removed. 

 The left optic nerve remains visible only in the form of atread 

 of nonmedullated fibres. Of the ganglia of the mesencephalon, 

 cerebellum, etc. all are intact. 



This dog which, as you see, had lost almost the entire cere- 

 brum, possessed the greater part of those faculties which for a time 

 we have been led to believe eminated essentially from the cere- 

 brum. The experiments of Goltz, which have removed so large 

 a mass of brain substance, have always produced great interest. 

 But the results of these operations, which he described in his 

 usual masterly manner, seemed to many to contradict the results 

 of the majority of the physiologists who have employed stimu- 

 lation and exterpation. In other words, a distinct contradiction 

 was thought to exist between the results of localization and those 

 produced by Goltz. Here, however, we must be content with 

 the facts. It is possible to explain that, on one hand, a slight 

 injury of cortex in man or the ape produces evident symptoms 

 or lameness, motor insufficiency, etc., that we may diagnose the 

 spot and treat it successfully, and that, on the other hand, this 

 dog, and many others operated upon by Goltz, gave evidence of 

 no marked motor disturbances. 



I am convinced that the facts which comparative anatomy 

 has taught us are well adapted to thro w a strong light upon the 

 significance of the cortex and cerebrum and to explan the con- 

 tradictions which so many find between the results of stimula- 

 tion of the cortex and its total extripation. 



There is a large class of animals which are totally devoid of 

 a cortex and the fibres originating there. It is the gronp of bony 

 fishes [Teleostei.] In this group the brain " begins ", sii venia 

 verbo, with the axial ganglon, corpus striatum, as indicated in 

 the drawing. The thalamus ganglia are relatively insignificant, 

 it is only when we reach the mesencephalon that great cell and 

 fibre masses appear. I may add that these do not differ in es- 



