A STUDY OF GROWTH IN THE SALAMANDER, 

 DIEMYCTYLUS VIRIDESCENS 



BY 



ADA SPRINGER 



Part i 



I Introduction i 



II Normal rate of growth 4 



III The rate of starvation 5 



IV Effects of varying amounts of food 6 



V The effect of injury on the rate of growth 7 



VI Rate of decrease during starvation in normal animals and in those with the tail removed .... 12 



VII Rate of growth after starvation 12 



VIII Effect of temperature on the rate of growth and on the rate of star\'ation 13 



IX Relation of growth to moulting 15 



Part n 



I To what factors are due irregularities in rate of growth 16 



a Males and females 16 



h Initial weight of animals 18 



II Influence of temperature on the rate of growth 21 



III Results of Part I interpreted in the light of the facts obtained in Part II 25 



IV Theoretical discussion 29 



V Summary 30 



PART I 

 INTRODUCTION 



For the purpose of studying the rate of growth and the external 

 factors that influence its rate, the spotted salamander, Diemy- 

 ctylus viridescens, has several advantages. It lives well in 

 confinement, it takes food readily from the hand, and can be 

 fed on pieces of beef; it withstands injury and can live for a long 

 period without food. 



The factors taken into consideration in this paper are four: 

 (i) food, (2) starvation, (3) injury and (4) temperature; the re- 

 sults being based upon experiments carried on between October, 

 1906, and May, 1908. 



The Journal of Experimental Zoology, vol. vi, no. i. 



