NATURAI. HISTORY OF AMERICAN LOBSTER. 1 85 



some cases the burrows were under rocks, and the entrance was often much larger than 

 that described, possibly owing to the union of the mouths of two originally distinct 

 burrows. The pile of, dirt and the broken clam shells which are sometimes seen near 

 the hole of the lobster recall the excavations of the muskrat. It was exceptional to 

 see a lobster with his tail projecting from the burrow, and when disturbed in this posi- 

 tion they were quick in disappearing. 



In digging, lobsters probably make use of their large claws and walking legs, and 

 possibly the tail fan may be brought into service as a scoop or shovel, but we have no 

 observation in support of the latter supposition. Yet, in some cases we have noticed 

 the underside of the tail fan to be scratched and scarified, and the marginal fringe of 

 hairs worn down in a way to suggest the probability of such use. 



Mead {193) found that the young lobster sometimes burrows in its fourth or 

 lobsterling stage, and this instinct is very pronounced in all its later phases. It removes 

 bits of gravel presumably with its claws and deposits them short distances away, thus 

 digging to a depth of 2 or 3 inches. Young lobsters, like the old ones, hide in their 

 holes, and issue stealthily in search of prey. Indeed, it may be said that such com- 

 manding instincts of the adult as preying, concealment, and fear, are manifested sud- 

 denly and for the first time in the fourth stage. 



The burrowing habits of certain species of crayfish are well known, while those 

 of the stomatopods (see chap, i) are equally characteristic. We meet with the 

 same habit in many snapping shrimps, expressed in a greater or less degree in terrestrial 

 crabs, and in a great number of the lower Crustacea. 



FOOD AND PREYING HABITS. 



The food of the adult lobster consists principally of fish, alive or dead, and of 

 invertebrates which inhabit the bottom and come within its reach. It is not unusua l 

 to find bits of algae or common eel grass in its stomach, and at f imps in sn rh giiflnt ^iHps; 

 as to suggest that it may not be an accidental occurrence. Vegetah ip matfpr, hnwpvpr, 

 forms at most but a small and casual part of its diet. Fragments of dead shells, coarse 

 sand, and gravel stones as large as duck shot are also swallowed '^^f fo rmer yield 

 lime, which is in some measure absorbed: the latter are not needed in grinHi np;_tVip fnnrl 

 as in the gizzard of the domestic fowl, since the lobster's stomach has, as is well known . 

 a. mill admirably adapted for this purpose, and their occurrence is probably accidental. 



I have dissected soft lobsters, with fragile papery shells, from 1 Vo to a V^ inches long . 

 in which the stomach was literally cramrr |p'^ ^^fln watPi--wnrn rglp areous fra s ^ments 

 of the dead sh ells of crustaceans and moUusks such as one can gather on the beach , 

 besides other sh ells of moUusks which had undoubtedly been eaten alive. This sug- 

 gested the possibility that the supply of lime for hardening the new shell might at 

 times b e obtained in this way (see 14.9; p. 89-90) for it seemed hardly probable tha t 

 J: h.ey would be swallowed to be immediately regurgitated . The lobster undoubtedly 

 regurgitates the insoluble and indigestible parts of its food, as is the known habit of 

 crayfish. Some such outlet for waste matter is absolutely necessary in an animal 



