GROWTH OF AMPHIBIA AFTER THYROIDECTOMY 



13 



apart; the rima oris increases in size and changes in shape; the 

 nostrils become relatively more lateral in position and larger, 

 and the legs increase from one-half to two- thirds (table 2) . 



The thyroidless larvae after the season of normal metamor- 

 phosis still resemble young larvae in general shape, but they 



Length and volume of larvae and frogs. Showing the variations in the length and 

 volume of living and fixed larvae. The animals were fixed in picro-formo-acetic 

 and preserved in alchohol. Note the small size of the frogs, which are only one- 

 third to one-half the volume of the larvae from which they are transformed. Vari- 

 ations in shrinkage occur during fixation . 



N-A., Nose-anus length; Tot., total; Vol., volume. 



have undergone a few changes (figs. 18 and 19). The tail has 

 become relatively long, the eyes are wider apart, the dorsum 

 of the head is slightly flattened, and the legs have increased 

 very slightly in length. During the winter and the second 

 spring and summer the thyroidless larvae (figs. 10 and 11) make 

 a still nearer approach in form to that of the frog. The legs 



