NATURAL HISTORY OF AMERICAN LOBSTER. 
177 
HABITS AND INSTINCTS OF THE ADULT LOBSTER. 
At this point we shall examine certain facts in the general natural history of the 
lobster, leaving, however, such important subjects as reproduction, growth, and 
development for special consideration. 
The sea bottom is the natural abode of the lobster, as it is of all the large and 
heavy Crustacea, the source of its food and the scene of all its activities, from the 
close of free pelagic life to old age. Its external world is the ocean floor, to which it 
reacts, and it knows no other. While its powers of locomotion are considerable, it 
never forsakes the water of its own accord or leaves the bottom, to which nature has 
consigned it by giving it a heavy body and a sedentary disposition. Lobsters wander 
close to the shore and out to depths of over a hundred fathoms, and the nature of the 
bottom, or more directly the supply of food, as well as the physiological condition of 
the animals, especially in respect to their molting periods, determine their abundance 
within these limits in any locality. 
The supply of food, the temperature of the water, and in general the physical 
conditions of the environment vary greatly throughout the range of this animal, as one 
might infer from a study of the coast line. From Labrador to Maine the coast is very 
rugged, deeply indented with bays, and studded with islands, some of which present 
perpendicular walls to the sea. The coast of Maine, particularly in its eastern and 
middle sections, is essentially bold, rocky, and diversified to an extraordinary degree 
by deep channels, extensive bays, and inlets of all kinds, and these are studded with 
rock-ribbed, spruce-clad islands. The geological formation is pre-Cambrian, the rocks 
being mainly granites. From 10 to 30 miles from the shore we find large and important 
islands standing alone or closely related, as Monhegan Island and the Vinal Haven and 
Matinicus groups. All are essentially masses of granite, which in some cases have been cut 
by glacial forces into archipelagoes; they abound in basins and channels of various 
kinds, into which fresh sea water is driven with every tide, and thus form admirable 
breeding grounds for food fishes, the lobster, and a host of invertebrates. The Cape 
Cod region is distinguished for its extensive sand shoals, which resemble those of North 
Carolina. The northern part of the Massachusetts shore is rocky, while the southerly 
portions are very diversified, abounding in submerged ledges, sandy and weedy bottoms, 
a great variety of bays and channels, as in Vineyard Sound and neighboring waters. 
Here lobsters were once exceedingly abundant, until they were nearly exterminated 
by the fishermen. 
Under the variety of conditions indicated we should expect not only to find lobsters 
larger and more abundant in some localities than elsewhere, a condition greatly influenced 
by the number and persistence of the fishermen, but also to meet with variations in 
the time of egg laying and hatching, of molting, and in the rate of growth. 
This animal spends most of its time in the search for food and in reproducing its 
kind. Its instincts are constantly leading it to secure protection through concealment, 
and we find it burrowing in the mud or sand, or hiding under stones, whether to await 
its prey or to pass in greater security the crises of its successive molts. 
48299° — Bull. 29 — 11 12 
