476 



Victor E. Emmel 



On July 25, 1907, seventeen specimens were mutilated on the 

 day following the moult to the fourth stage. Each lobster was 

 mutilated by the autotomous removal of the right chela. The 

 results are shown in Table II. 



TABLE II 



Lobsters in the fourth stage. Original chela symmet'ical. Right chela removed 



* Specimens 9 to 17 moulted to the sixth stage a few days after July 16, but the date of moult was not 

 recorded. 



It is readily seen that these results show a marked uniformity. 

 Without exception the mutilated claws became nippers; the claws 

 which were not mutilated became crushers. 



LOBSTERS IN THE FIFTH STAGE 



The fifth stage is especially important because, normally, at the 

 next moult asymmetrical characters are displayed. Consequently, 

 during this period there must be a rapid progress in the differen- 

 tiation of the chelae. 



