232 
ANIMAL INTELLIGENCE. 
The land crabs of the West Indies and North America 
descend from their mountain home in May and June, to 
deposit their spawn in the sea. They travel in such swarms 
that the roads and woods are covered with them. They 
migrate in a straight line, and rather than allow them- 
selves to be deflected from it, 6 they scale the houses, and 
surmount every other obstacle that lies in their way’ 
(Kirby). They travel chiefly by night, and when they 
arrive at the sea-shore they 6 bathe three or four different- 
times , 5 and then 6 commit their eggs to the waves . 5 They 
return to the mountains by the same route, but only the 
most vigorous survive the double journey. 
Prof. Alex. Agassiz details some interesting observations 
on the behaviour of young hermit crabs reared by himself 
6 from very young stages , 5 when first presented with shells 
of mollusks. 6 A number of shells, some of them empty, 
others with the animal living, were placed in a glass dish 
with the young crabs. Scarcely had the shells reached 
the bottom before the crabs made a rush for the shells, 
turned them round and round, invariably at the mouth, 
and soon a couple of the crabs decided to venture in, 
which they did with remarkable alacrity . 5 The crabs 
which obtained for their share the shells still inhabited 
by living mollusks, 6 remained riding round upon the 
mouth of their future dwelling, and, on the death of the 
mollusk, which generally occurred soon after in captivity, 
commenced at once to tear out the animal, and having 
eaten him, proceeded to take its place within the shell . 51 
There is a species of small crustacean ( Podocerus 
capillatus) described by Mr. Bates, which builds a nest to 
contain its eggs. The nest is in the form of a hollow 
cone, built upon seaweed, and composed of fine thread- 
like material closely interlaced. 6 These nests , 5 says Mr. 
Bates, ‘ are evidently used as a place of refuge and security, 
in which the parent protects and keeps her brood of young 
until they are old enough to be independent of the 
mother’s care . 5 
Dr. Erasmus Darwin tells us, on the authority of a 
friend on whose competency as an observer he relied, that 
the common crab during the moulting season stations as 
1 American Journ . Sc. and Art , vol. x., Oct. 1875. 
