232 



Comparative Animal Physiology 



1300 - 



1200 - 



1100 - 



>: 1000 - 



900 



-I 800 - 



700 - 



600 I 



Fig. 50. Metabolic peak in Rhode Island Red chickens at end ot first month 

 after hatching. From Kibler and Brody.""" 



100 



200 300 400 

 AGE IN HOURS 



500 



600 



Fig. 51. Respiration of Amblystomn embryos e.xpressed as m/il- 0../100 ngm. dry wt./ 

 hr., showing break in developmental rate at about seventh day. Arithmetic and loga- 

 rithmic curves jilotted from same data. From Boell.'" 



