A Study of Groivth 27 



After 



In. wt. operation Increment In. wt. Increment 



grams grams per cent grams per cent 



Set H^ I 446 1.27 31.6 Set H2 1.65 20.3 



The difference in the initial weights was not great, therefore the 

 percentage may be taken as showing more nearly a correct relation 

 between the injured and the normal sets. 



In Sets F''^ (Table X) in which animals were injured by cutting 

 regenerating stumps, in F^'^ (Table X) in which the regenerating 

 stumps were left intact, and in H- (Table IX), the normal control 

 set, the initial weights and the percentage increments were as 

 follows : 



Ajter 



In. wt. operation Increment In. wt. Increment 



grams grams per cent grams per cent 



Set Fia^ 1.345 1.268 21.8 Set Fib j^^^ 23.5 



Set H2 1.65 20.3 



This is the only case throughout the experiments, however, 

 where the percentage increment was not greater in the injured 

 set. 



In Sets P, P, P (Table XII) the tails were cut six successive 

 times, and the conditions of food and temperature were identical. 

 The initial weights and the percentage increments of the injured 

 sets together with those of the normal controls, A^ and A% were 

 as follows : 



Ajter 



In. wt. operation Inc-ement In. wt. Increment 



grams grams per cent grams per cent 



Set I' 1-733 1-4^5 4-- Set Ai 2.066 23.3 



Set I- 2. 1 18 1-733 24 -5 Set A2 1.661 29.8 



Set P 2.489 1 .977 23 .5 



Initial weights here also seem to account for the irregularities. 

 That the percentage in Set P is greater than either P and P, is 

 probably due to the fact that the average initial weight is con- 

 siderably less. This is true also in the control Sets A^ and A^. 



From the comparisons cited above it is found that in some of 

 the cases the initial weight of the injured sets (before the tails 

 were cut) was greater than that of the intact control sets, while 



