84 Charles Zeleny. 



where only one chela was removed. This statement is of course 

 not a definite quantitative one on account of the difficulty in esti- 

 mating relative sizes, but becomes interesting in connection with 

 the following results on Alpheus (p. 85, ffl.) and the former 

 cases already described. 



The results, therefore, indicate that where two chelcB are removed 

 the time of moulting is hastened and the rate of regeneration of each 

 chela IS increased as compared with the cases where only one chela is 

 removed. 



4. Rate of Moulting after Removal of One or Both Eyestalks. 



(Male and Female.) 



Three sets of experiments were performed. 



a. In one set of three females the right eyestalk was cut off 

 near its base. Pigment very soon collected near the cut end so 

 that the region assumed a color much darker than the normal eye 

 color. A similar change took place in all the other experiments 

 after the cutting of the eyestalk. 



h. In another set there were three males, one with the large 

 chela on the left and two with it on the right side. The right eye- 

 stalk was cut off near its base. The first noticeable change as in 

 the last set was a collection of very dense pigment at the cut surface. 

 All three of the specimens moulted before the close of the experi- 

 ment, one 56 days, another 58 days and the third 61 days after the 

 operation. At moulting the dark pigment of the cut surface dis- 

 appeared and the end of the new eyestalk was rounded and 

 resembled the old eyestalk except that it was shorter. 



c. In a third set of four males and one female both eyestalks 

 were cut ofi^ near their bases. Two of the specimens lived for 

 more than a few days. One moulted 14 days after the operation 

 but was found dead and broken after the moult. In the other 

 one the cut surfaces of the eyestalks were black with pigment at 

 this time and also five days later, 19 days after the operation. 

 This specimen moulted 23 days after the operation, at which time 

 the eyestalk ends were rounded but there was no appreciable 

 increase in eyestalk length. The very dark pigment disappeared 

 with the moult as in the last series. The animal died 40 days 

 after the operation. 



d. Conclusion. In the specimens with an eyestalk operation 

 the time of moulting was hastened as compared with unoperated 



