386 G. G. SCOTT. 



tion is evident after the first few days after operation. In order 

 to further test this point and ascertain whether lack of food had 

 anything to do with the result, two lots of fishes were operated 

 on in a similar manner on September I. Each lot was placed 

 in a jar in three liters of sea water and both jars placed in the 

 ice chest. One lot was fed and the other not fed. On Septem- 

 ber 14 nine tenths of those that had not been fed had survived 

 and seven tenths of the others. There was no sign of regenera- 

 tion in either lot. It might be added that in case of another 

 experiment set up at the same time that regeneration was evident 

 a few days after. (See Table III.) 



It may be of interest to note that two of the survivors men- 

 tioned in the first experiment were placed in a shallow jar sur- 

 rounded by running sea water, and in two weeks time the caudal 

 fin showed a regeneration of 2 mm. indicating that just as soon 

 as the temperature was raised to the normal regeneration began. 

 It should also be noted that the temperature necessary to inhibit 

 regeneration was not an extremely low one, and that this indi- 

 cates that the power of regeneration is sensitive to lowering of 

 temperature. 



(B) RELATION OF AMOUNT OF INJURY TO REGENERATION. 



In 1902 Zeleny observed that when two chelae of Gclasinnts, 

 the fiddler crab, were removed each of the regenerating buds 

 grows more rapidly than does the single one when only one chela 

 is removed. In 1903 the same author found that the regeneration 

 in the arms of the brittle star-fish, Ophioglypha lacertosa, varies 

 with the number of arms removed, /. e., that animals with the 

 greater number of arms removed regenerate more rapidly. The 

 greater the degree of injury the more rapid the regeneration. In 

 1905 Zeleny in an experiment extending over 181 days using the 

 common cray-fish, Cambants propinquns, found that in the series 

 with the greater degree of injury (Series B) each chela regen- 

 erates more rapidly than the single chela of those with the lesser 

 degree of injury (Series A), in Series A consisting of 36 indi- 

 viduals the right chela was removed at its breaking joint. In 

 series B consisting of 41 individuals the two chelse and the last 

 two pairs of walking legs were similarly removed. It is to be 



