182 JOSEPH DUERSON STOUT 



The opinions of various investigators as to the equivalent in 

 the brain of the cat of the fissure of Rolando in the brain of man 

 and the higher monkeys, have varied considerably from time to 

 time. To quote from Ferrier: 



The crucial sulcus has been regarded by some as the homologue of 

 the fissure of Rolando. Others (Meynert, Pansch) regard the coronal 

 fissure as the true homologue; while Broca finds it the prae-Sylvian 

 sulcus, or sulcus bounding the gyrus formed by the anterior extremi- 

 ties of the lower three external convolutions. 2 



Ferrier discards the prae-Sylvian sulcus and the crucial sulcus, 

 but is inclined to accept the coronal fissure as the Rolandic 

 analogue. This is contrary to the later opinion of Campbell, as 

 has been indicated above, but the criteria of Campbell and of 

 Ferrier are, it should be noted, not the same, the former de- 

 pending upon anatomical examination, while Ferrier has taken 

 the physiological point of view. The conclusions of Ferrier in 

 this regard are to be compared with the results which are re- 

 ported in later sections of this paper. 



Frangois-Franck has not definitely located the various points 

 on the cortex which he stimulated other than to describe them 

 as points for the movement of the crossed fore limb, etc., so it is 

 necessary to deal with his results in some cases with much 

 reserve in comparing them with the results from definitely 

 located points. 



Methods 



The animals used were adult cats. Each was first anaesthet- 

 ized in a box and while unconscious strapped to an animal 

 holder. Anaesthesia was then maintained throughout the ex- 

 periment with the A. C. E. mixture. 3 In the animals first oper- 

 ated upon, two f-inch trephine openings were made in the skull 

 and the openings were then enlarged with bone forceps, backward 

 and to the front and side. By this method difficulty was ex- 



2 D. Ferrier: Functions of the Brain. 2d edit. 1886, p. 346. 

 8 This is a mixture of 1 part alcohol, 2 parts chloroform and 3 parts ether, 

 frequently used in animal experiments and sometimes as an anaesthetic for man. 



