The Journal of 

 Comparative Neurology and Psychology 



Volume XV 1905 Number 5 



A STUDY OF THE FUNCTIONS OF DIFFERENT 

 PARTS OF THE FROG'S BRAIN. 



By WiLHELM LOESER, M.D, 



{From the Physiological Laboratory of the University of Kansas.) 



As a contribution to the study of the comparative physi- 

 ology of the brain, it seemed important to undertake a more de- 

 tailed investigation of the functions of the different parts of the 

 frog's brain than had hitherto been made. 



The work done by me under the supervision of Dr. Ida 

 H. Hyde — to whom I am under great obligations — can, at best, 

 constitute only a small link, in the long and complex chain of 

 comparative physiology. The experiments extended over a 

 period of two and a half months, and the material operated on 

 consisted of more than fifty frogs of the species Rana tempo- 

 raria. 



I employed Goltz's method, i, e., that of excising vari- 

 ous parts, or aggregations of parts, of the central nervous sys- 

 tem, and observed the resulting phenomena, particularly the 

 deficiency phenomena. Both uni- and bilaterial excisions were 

 resorted to. The animals were anaesthetized with ether until 

 they would not readily turn over on the ventrum when put 

 on the dorsum, but would respond only with convulsive jerks 

 of the muscles of the limbs. For operations on the medulla 

 the anaesthesia was carried further to prevent movements during 

 the operation After the frog had reached this stage of anaes- 

 thesia, it was tied with its ventrum upon the frog board. A 

 sponge moistened with ether and placed in front of the nares was 

 sufficient to keep the animal in the desired stage of anaesthesia 



