Il THE SERVICE OF TAILS 69 
the body, the other two braced themselves against 
me and pulled on the tail with all their strength, 
to uncoil it. We wrestled with it until we were 
fairly exhausted, failed utterly, and gave up beaten. 
Such was the wonderful power in the tail of that 
small animal.” 
As a receptacle and carrier of eggs the tail parts 
of certain among the lower animals serve an im- 
portant purpose in their economy. In the lobster, 
and its miniature, the fresh-water crayfish, the 
latter segments of the abdomen form a fan-shaped 
tail, on the under surface of which are small ap- 
pendages called swimmerets. When the eggs have 
ripened between the ovaries of the female (whose 
swimmerets are especially adapted to their purpose, 
and different from those of the male), they are ex- 
truded from openings in the second pair of legs, 
just back of the great front claws. These eggs 
are covered with a viscid matter, something like 
those of the frog, which is readily drawn out into 
threads. These threads become entangled with 
the hairs covering the swimmerets, and thus sev- 
eral hundreds of eggs attach themselves to each 
swimmeret, and appear as large grape-like bunches, 
filling the whole space beneath the tail. Here they 
develop under the most favorable conditions, and 
‘after the young have hatched, these hold on to the 
swimmerets, and are carried about and protected 
by the mother until they are able to care for them- 
selves. Here is another caudal nursery. 
