NATURAL, HISTORY OF AMERICAN LOBSTER. 273 



moth lobsters generally. The cracker claw of this giant is remarkable for its swollen 

 ovoidal form, its girth being loyi inches, and for its worn and blunted tips; the blunt end 

 of the "hand" is even recessive, the tubercular margin being convex as is frequently 

 noticed in very large animals, and this in spite of the fact that the big molars are worn 

 nearly flat. The worn-ofif end of the dactyl strikes about midway on the big distal 

 tubercle, while the arrangement of the tubercles themselves is typical and essentially 

 that given above; the propodus showing only two big "crushers," with one small inter- 

 mediate and two paired or double proximal tubercles. 



In the lock forceps of this specimen the hooked points are broken, rasped, and worn 

 down, while its serrated margins are slightly convex, as is often the case in the fourth 

 or fifth stage. The dactyl of this claw presents 7 to 8 primary spines. The huge, 

 pyramidal lock spine of the propodus is much worn, and the first period distal to this 

 bears 10 spines, having the formula: 1 + 1+2 + 4+2 = 10. Then follows a long and 

 probably compound period of 17 spines; then a primary spine and several smaller ones 

 opposite the "spur." Thus, in this huge clawfrom lock to spur there are only three or at 

 most four periods represented, as in all the younger stages hitherto discussed. This again 

 illustrates the fact that while the procession of spines is constantly "on the move," 

 the "dental formulae" for the toothed claw never being identical for any two successive 

 molts, the losses are so well balanced by the gains that the toothed claw, which attains 

 its characteristic form from the fourth to the seventh molt, remains essentially unchanged 

 throughout life. 



We have seen how the toothed type of claw, which Stahr considers an ornament 

 fitted to please the "aesthetic sense" of these animals, has arisen, but the wonder is 

 not that the teeth are arranged in periods of eight, but that they are developed in order 

 at all. The problem is similar to that of the orderly arrangement and appearance of 

 the paired mesentaries of certain coral polyps, and fundamentally the same as that 

 of the orderly development of the parts of all organic bodies, concerning the mechanics 

 or the regulative control of which nothing is definitely known. 



When we consider the known structure and development of the great claws in 

 relation of the known habits of their possessor, we find no warrant in considering them 

 as an "ornament" or in any other light than that of most efficient tools and weapons, 

 chiefly for defense, for the capture of prey, for rending it in pieces, and afterwards for 

 handing over the edible parts to the grinding mechanism which begins with the mouth 

 parts and ends in the stomach. The developmental history of the lock forceps and its 

 periodic teeth, as narrated above, renders any criticism of Stahr's fantastic theory, on 

 the ground of comparative psychology, superfluous. 



On the inner margins of the great claws appear certain prominent spines (fig. 2, 

 pi. XXXVII up. ser., and I. ser.), which are very regular in form and position, but vary 

 somewhat in number. They consist of an upper series of 4 to 6 stout spurs curved 

 upward and forward, and a lower of i to 3 teeth of lesser size, alternating with the first, 

 and bent downward and forward. They probably originate from a single series, by 

 displacement. They are eminently protective, while the proximal and often double 

 spur on the upper side may act as a buffer when the claw is folded inward. Greater 



