Crustaceans. 5 1 



in a suitable place. And besides all the other 

 water creatures that relish fresh eggs, the fishes 

 themselves are sad cannibals. 



Although they will not eat their own eggs, many 

 do not hesitate to devour the eggs of other species, 

 wherever they can find them. 



So the million eggs of a cod are none too many 

 to insure even a small progeny to each fish. 



Not all creatures are as prodigal of life as are 

 the fishes, however. 



Many have most elaborate structures for the 

 preservation of the reproductive cells until they are 

 hatched. 



The lobster, for instance, cannot trust its precious 

 life-cells to the tender mercy of the creatures of the 

 deep. It preserves its eggs and sperm-cells, and 

 ingeniously adapts its jointed body to the uses of a 

 nursery. 



Recall the structure of the lobster in order to 

 understand this. 



There is a solid front portion of the body to 

 which the legs are attached, and a hind portion 

 which is in rings, like the body of a caterpillar. 



Two little leaf-like parts, or swimmerets, are 

 attached to the under side of each ring. The 

 openings of the egg-tubes are found on the inner 

 joint of the third pair of legs, counting from the 

 back; and in the male the openings of the tubes 

 to the sperm-sacs are found on the inner joints of 

 the last pair of legs. In the male the last two pairs 



