128 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



C. Resume. 



a. The normally asymmetrical chelae of two adult lobsters were 

 autotomously removed. The right claw of lobster No. 8 was a 

 "nipper," and the left a ''crusher;" in lobster No. 9, left was the 

 nipper, and the right a crusher. 



b. After amputation the chelae of both lobsters regenerated, but 

 the regenerative processes did not reproduce the original asymmet- 

 rical types of chelae. The regenerated left claw of No. 8 and the 

 regenerated right claw of No. 9 were both true "crushers" like the 

 original claws; but the regenerated right claw of No. 8 and the left 

 of No. 9 had the general characters, not of the original "nipper," 

 but of a typical " crusher." 



c. A close analysis of the structural features of the latter two 

 regenerated claws demonstrated that, in all their morphological 

 characters, they respectively, corresponded point for point, with 

 both the normal and the regenerated crushers of the opposite sides, 

 in respect to the general form, size, and proportions, in the shape 

 and arrangement of the teeth, and even in the number and distribu- 

 tion of the tufts of tactile hairs. 



The regenerated claws 'of these two lobsters are, therefore, symmetrical 

 in form, and in both specimens they are of the "crushing" type of 

 cheloe. 



IV. 



DISCUSSION. 



1. Frequency of Occurrence of these Various Types of Abnormalities. 

 Specimens Nos. 1 and 2. (Figs. 1 and 2.) 



Cases of extra processes arising from the dactyl are the most 

 common of crustacean deformities. For the lobster, Faxon describes 

 at least three cases similar to specimen No. 1, with two extra pro- 

 cesses upon the smooth border of the dactyl, (Faxon, Plate I, 

 Figs. 1, 2, and 8). He further states that "there are several speci- 



