146 REPORT OF COMMISSIONERS OF IXLAND FISHERIES. 



peculiar;" or, again, that probably "such a monstrosity as this 

 might arise in regeneration following an injury to the propoclite" 

 (p. 83). 



Herrick, ('95) on the one hand, is inclined to favor the regeneration 

 theory for these deformities. Although he points out that "repeti- 

 tion of parts, however, occurs in many insects and vertebrates where 

 no such regeneration of lost appendages is known," he finally con- 

 cludes that "while it would appear that the various deformities 

 which have been described can not be explained as the result of 

 injuries and the attempted regeneration of injured parts, .... 

 yet I can not escape the conviction that the problem is in some way 

 directly concerned with that of regeneration" (p. 148). 



But in regard to lobsters with similar chelse, Herrick evidently 

 favors the congenital theory; for in his discussion of symmetrical 

 chelse, he states " That there seems to be about as much variation as 

 regards the details here mentioned in normal symmetrical claws as 

 in the abnormal symmetrical ones, and it is probable that in either 

 case the conditions met with are to some extent congenital" (p. 144). 

 Quite recently Dr. Caiman's ('06) case of a lobster with two crusher 

 claws has been interpreted as further discrediting the regeneration 

 theory for symmetrical chelae, as may be seen in the following state- 

 ment : " It has been supposed that this might be due to regeneration 

 after injury, since it is known that in Brachyura, on the removal of 

 the crushing claw, a cutting claw is regenerated. Przibram,* how- 

 ever, failed to obtain such " heteromorphic " regeneration in the 

 lobster, and the present specimen throws still further doubt on the 

 regeneration theory, since it possesses well-developed and quite 

 typical crushing chelse on both sides of the body" (p. 634). 



In this brief review of theories for abnormal chelae, it appears that 

 the majority of the above investigators have emphasized the origin 

 of such abnormalities through congenital sources, and injuries after 

 moulting ; while others have discussed the possibility of their being 

 regeneration products. But it is important to note that in no case 



*'02, p. 12, and '05, p. 191. 



