[mills] cortical cerebral LOCALIZATION 27 



the animal is sufficiently from under its influence soon after the main 

 operative procedure is over to allow of results being obtained at once, and 

 unless the loss of 'blood be excessive I have always found it wise to pro- 

 ceed at once before the brain suffers by exposure. 



However, after Dr. Mann's paper met my eye I determined to test 

 his results by his own methods as regards the centre for the hind-liml) in 

 the rabbit, which T had never been able to find. The result agreed pre- 

 cisely with all my previous experience, to the effect that movements in an 

 animal anaesthetized inadequately or not at all anaesthetized following on 

 stimulation are hap-hazard. They may be in accord with those obtained 

 under the use of an anaesthetic or they may be utterly delusive. It 

 counts nothing with me that the same movement may be called forth 

 over and over again on stimulating the same spot, for I have pro- 

 duced repeated movements of the hind-limb by stimulating the neck, 

 area, etc. 



Mann mentions that in one of his expeinments on rabbits " both 

 hind-legs kick out as in ordinary locomotion." (p. 26). Such a result 

 in a mature rabbit should surely be viewed with grave suspicion, especi- 

 ally by one who claims such exact localization as Dr. Mann. 



My own results on the rabbit may be thus briefly stated : 



I have without any difficulty been able to localize cortical centres 

 for a variety of movements for the fore-limb, the neck, head and face ; 

 with more difficulty, movements for the eyes and the ears ; but in no 

 single case when the animal has been properly under the influence of 

 ether have I been able to get movements of the hind-limb by stimulation 

 with any reasonable strength of current. A large number of animals 

 of different breeding, some being cross-bred, some pvire-bred, and some 

 ordinary mongrels, and of varying age, have been employed. 



I can only explain the positive result that some other investigators 

 report by the assumption that their animals were not at the moment 

 properly under the influence of an ana'sthetic, and that a hap-hazard 

 movement was mistaken fcft* a genuine one. Certainly it would be 

 strange, after so much experience in this kind of work and after subject- 

 ing this question of a centre for a hind-limb to special investigation Avith 

 the use of so many animals of different breeding and age, that my 

 results should be uniformly negative for this centre, but positivée for all, 

 or nearly all others found by experienced investigators, if I am in error. 

 I caii endorse what Fiirstner ' has said with regard to the ease with 

 which chewing movements may be obtained in rabbits, and I have pointed 

 out in my paper '^ on the functional development of the cortex that 

 these and such like movements appear far earlier in the rabbit than in 



i"Exper. Beitrag, z Electrisch. Reiz. d. Hirnrivde." Archf. Psych, vl. pp. 

 719-732. 



'■^ The.se Transactions for the current year. 



