REPORT OF (X)MMISSIONERS OF INLAND FISHERIES. 131 



farther. And this case is evidently the nearest approach to a true 

 tripUcation of the chela yet discovered in the lobster. 



Specimen No. 6. (Figs. 6-9.) 



Normally in the adult lobster the "great claws" are almost 

 invariably asymmetrical with reference to each other — the claw on 

 one side being a "crusher" and the other a "nipper." The crusher 

 claw seems to occur about as frequently on one side of the body as 

 the other,* but it is only very rarely that we find an adult lobster 

 with both chel£e alike. In examining over 2,400 lobsters Herrick 

 ('96) found only 3 which had similar claws on each side of the body 

 (p. 143); and in a personal examination of over 600 specimens as 

 they came from the traps at the experiment station, I found only 

 one lobster with both claws alike. This specimen, therefore, makes 

 the fourth lobster out of 3,000 which has been found with both claws 

 alike. It is important, moreover, to note here that these four cases 

 were all of the ^'nipper" type of chelae. 



Specimen No. 7. (Figs. 10-18.) 



This case of a triple claw is especially unusual because it occurs 

 upon a walking leg. The fact that such abnormalities are very 

 seldom found on a walking leg has been pointed out by Andrews*('04) 

 in his statement that: "Of the thirty cases of abnormal appendages 

 quoted by Bateson, two are of the antennae, four are of non-chelate 

 legs, and all the rest of chelae except one, which is a chelate walking 



leg and of the eleven additional cases given by Herrick, 



only two are of the walking legs" (p. 81). 



Incomparing the present specimen with other described cases in 



*It is an interesting question whether this right and left "handedness" of the lobster is 

 inherited and congenital, or whether it may be determined during development and by other 

 factors. I hope later to give the results of some experiments now almost completed, in which 

 I have tried to throw the crusher to either side of the body by making appropriate mutilations 

 during the larval stages; i. e., at a stage before the claws have differentiated into crusher or 

 nipper. For a further discussion of this subject see an article in Science (Emmel, '07), in which 

 it is shown that the results so far attained in these experiments estabhsh a strong presumption 

 that the right or left handed asymmetry of the lobster may be determined by other than 

 hereditary factors. 



