CRABS AND SHRIMPS. 



179 



animals are hatched, but until they have acquired a suffi- 

 cient maturity to swim about and get their independent 

 living. 



This receptacle, in which you may see five or six eggs, 

 is freely open to the surrounding water, which enters 

 the slit edge of the shell behind the tail. Perhaps you 

 wonder why the eggs are not washed out by the respiratory 

 currents ; they are, in fact, maintained in their position 

 only by a slender tongue-like projection from the back of the 

 parent, which appears to have that special object. When, 

 however, the young are ready for freedom, the mother has 



DAPHNIA. 



but to depress her body a little more than ordinary, when 

 the door is opened and the young easily slip from the re- 

 ceptacle into the open water. 



These tiny odd-looking sprawling things that you see 

 moving about by quick jerks in the same drop of water, 

 are the young recently hatched. They are quite unlike 

 their parent, having as yet no bivalve shell, no abdomen, 

 and only three pairs of limbs. The body is a transparent 

 plate, resembling the bowl of a spoon in form, but ending 

 in two points which carry pencils of bristles. The large 



n2 



