362 Charles Zeleny. 



values are .0030 ( ±.0001) for Series A and .0083 (±.0007) for 

 Series B. In each instance there is a very striking advantage of 

 the series with the greater injury over the one with the lesser 

 injury. This amounts to 63 per cent for the males and 177 per 

 cent for the females. The individuals with the two chelae and the 

 last two pairs of walking legs removed as compared with the 

 individuals in which the right chela alone is removed regenerate the 

 right chela more rapidly than do the latter. This takes place 

 notwithstanding the fact that at the same time they have also 

 to regenerate the left chela at the same rate as the right one and 

 also the last two pairs of walking legs. The individual therefore 

 which has the greater amount of material to regenerate regenerates 

 each part faster than does the individual with the smaller amount 

 of removed material. 



Relation hetweeii Rate of Moulting and Rate of Regeneration. 



The fact that the specific amount of regeneration is a constant 

 for all individuals of a sex makes the relation between the rate of 

 regeneration and the rate of moulting a very close one. One of 

 three possibilities in the relation of the two must be the true one. 

 The more rapid rate of regeneration of the limbs may be the cause 

 of the acceleration of the moulting or the opposite may be the case 

 or finally the two phenomena may be co-ordinate and only 

 indirectly related. If the first is the case the growing limb-buds 

 in pressing against their chitinous envelopes more vigorously in 

 Series B must be supposed to act as the stimuli for the increase in 

 the rate of moulting. If the second possibility is true the first 

 result of the operation is an acceleration of the rate of moulting 

 which secondarily affects the rate of regeneration. Finally it is 

 possible that the stimulus of the removal of the limbs acts directly 

 and independently upon both regeneration and moulting processes. 



y 



DISCUSSION. 



In opposition to the very common belief that an increase in the 

 degree of injury to an individual implies a lowering of its ability 

 to repair the sustained injuries the experiments on the several 

 forms mentioned above^ have shown that with an increase in the 



'Gelasimus, Alpheus, Ophioglypha, Cambarus (see pp. 347—362). 



