LOCOMOTION IN BATRACHOSEPS. 287 



than if they had been pendent enough so that the toes also 

 touched and dragged along the ground. 



(<r) Cooperation on the part of the hind-legs could be started 

 by touching with a pencil-point the skin of the sides of the body 

 posterior to the section in the cord, or by touching the toes or 

 the heels. 



(it] A number of specimens would walk perfectly normally on 

 their hind-legs when the front part of the body was held up and 

 carried forward slowly. The walking movements would begin 

 sometimes at once without dragging, sometimes after the hind- 

 legs were dragged for a distance. 



Experiments were made cutting Batrachoseps entirely in two 

 as Friedlander had done with earthworms. The section was 

 made at various levels between the girdles. Nothing but simple 

 reflexes were obtained from the posterior halves although the 

 pieces lived for days. The anterior halves, however, seemed to 

 suffer no depression whatever. As soon as they recovered from 

 the effects of the anaesthetic, they moved about in a manner that, 

 with the exception of the awkwardness produced by the absence 

 of the customary weight and resistance of the postetior parts and 

 of the exhaltation produced by the operation, was perfectly nor- 

 mal. One of these anterior pieces lived for twenty-four hours. 

 An hour before it died it was still breathing and moving about 

 normally. 



These results are about what one would expect to find in 

 Batraclwseps. For, unlike earthworms, they cannot depend 

 alone on the skin for respiration or upon an uncertain circulation. 

 After sectioning the body the posterior half is deprived entirely 

 of the benefits of the pharyngeal breathing and of the heart-beat, 

 which continue on in the anterior half uninterrupted. After cut- 

 ting an earthworm in two, respiration and the circulation can go 

 on in the posterior half as well as they do in the anterior half. 

 Hence the nervous responses in the one half are not different 

 from what they are in the other half. 1 



5. Summary and Conclusions. The results of the foregoing 

 experiments on Batrachoseps may be summed up, and conclu- 

 sions may be drawn, as follows : 



1 Friedlander, loc. cit., p. 190. 



