A Study of Growth 1 3 



individual of normal conditions. In animals that had been 

 starved for five weeks, and after that time were fed 153 mg. 

 (average) of beef, there was a marked acceleration of growth. 

 Four sets were starved for five weeks, after which they were fed 

 153 mg. (average) of beef. Four sets were taken as controls 

 which had been well fed for five weeks, after which time the same 

 amount, 153 mg., was given to each animal. The condition of 

 the animals at the beginning of the experiment was identical. 

 After four weeks the differences in percentage increments were 

 as follows: 



I After five weeks' starvation 2 After five weeks' of feeding 



Set H2 (Table IX) 20.3 Set Qi (Table VI) 11. 4 



Set pia (Table X) 21.8 Set E'^ (Table VII). 21. i 



Set Fib (Table X) 2^^ Set Eib (Table VII) 5.3 



Set F3b (Table XI) 27.8 Set E=b (VIII) 18.2 



The percentage increment after the period of starvation in every 

 case proved to be the greater. In many other sets this is also 

 shown, as Sets A^ (Table I); B^ (Table II); D^ (Table IV). 



Throughout the experiments another fact comes to light that 

 appears to be quite general, namely, that a very high percentage 

 of gain during one week is followed the next by a low percentage, 

 and in many cases even by a loss. This is most striking after 

 feeding individuals that have been starved; the first percentage 

 is very high, while those immediately following them are low. 



VIII EFFECT OF TEMPERATURE 



It is generally known that the rate of growth is accelerated 

 by warmth and retarded by cold. This has been determined for 

 the growing embryo and for regenerating parts. With the view 

 to determine the effect of temperature above and below the 

 normal (the normal in this case, being considered the room 

 temperature), upon the rate of growth and the rate of starvation in 

 adult salamanders, six sets, consisting of six individuals each, were 

 kept under three conditions of temperature, as follows: 



Two sets were kept at the normal temperature of the room, 

 averaging 22° C. The highest temperature recorded during the 



