CELL SIZE AND METABOLIC ACTIVITY IX AMPHIBIA. 355 



TABLE I. Continued. 



Chorophilus nigrilus. 



feces of having eaten recently. The baby specimen was killed 

 and blood smears made immediately at tin- termination of the 

 carbon dioxide output measurements; the adults were bled from 

 tin t.iil vein after six weeks. 



Neiturn'i nuiculosus (Ratinesque). All >prrimens except the 

 tir-t two used were collected from Lake Mendota at Madison. 

 They were kept in cold running water without food until used, 

 l-'rom the time of the first determination on an individual until 

 it w.is killed or died it was kept at room temperature. Till- 

 first two specimens were received from dealers, and their source 

 is unknown. In this sj>ecies starvation was carried on over a 

 loii^ period of time, and its effect on metabolism studied. Indi- 

 \idu.iU of widely varying weights were used and the effect of 

 \\eiijit on metabolism noted. The results of these experiments 

 will be described later. 



Cryptobranchus atteganiensis (Daudin). The single specimen 

 u-ed \\.i- .1 laboratory specimen of unknown source from which 

 blood Miu-ars were made. No individuals were available when 

 needed t. ir un tab ilisra tests count of the cold weal her. 



I^icmyctylns viridcscens (Ratinesque). One specimen was u>ed 

 tor blood MIHMI-. It was collected in New \'ork state during 

 the summer, and blood smears were made in the fall. Probably 

 the animal had not eaten in the meantime. 



Ran a catesbiumi (Shaw). Twelve specimens were obtained 

 from New Orleans. Specimen No. I had had the lower jaw 

 broken at some previous time, and it had healed in >uch a manner 



