Some Friends in Armor 1 09 



the dim outlines of the nascent larva. Each succeeding 

 day is marked by a gradual but very definite change in 

 the embryo; until finally the wee animal acquires a seg- 

 mented hind body, a large tail fan, and a pair of un- 

 stalked eyes. A more dissimilar offspring from the 

 crawling adult could hardly be imagined. Its muscular, 

 ringed abdomen and its broad tail now fit it preemi- 

 nently to lead a roving life at any depth. 



The moment for hatching comes. It has been sig- 

 nalized some hours before by a restless activity on the 

 part of the larva in its apparent efforts to burst the two 

 walls that confine it. Suddenly these are split length- 

 wise and the wriggling youngster emerges headfirst 

 through the rent. It has no chance to linger as it is 

 caught immediately by the respiratory currents of the 

 mother and sent hustling away. A common impulse 

 now seems to animate the brood, and within a few 

 hours the remaining larvae abandon forever the pre- 

 cincts of the maternal shell. The mother then de- 

 taches the swaddling clothes still adhering to her; and 

 soon following the departure of her young she sends 

 bag and baggage flying after. 



Thenceforth each little crab pursues its uncertain 

 fortunes alone. After a lapse of five or more weeks — 

 during which it molts not less than four times, increas- 

 ing in size and acquiring a more adultlike character 

 with each shedding of its crust — it settles to the bottom 

 and finds a tiny shell. 



Such is the manner in which the hermit crab is 

 ushered into the world. A rapid survey of his future 

 shows that before the winter gales will have forced 

 him into deeper water, where he will pass a dormant 



