Chap. 32 ECHINODERMS FORERUNNERS OF THE VERTEBRATES 661 



water. Other waste is probably carried away by escaping body fluid. There are 

 no kidneys. 



Reproduction. With few exceptions, the sexes are separate in starfishes. 

 There are two ovaries or two- testes in each arm with a minute opening in each 

 organ near the base of the arm (Fig. 32.7). In most species, the eggs and 

 sperm are discharged into the open water; fertilization occurs there, and 

 there is no trace of parental care (Fig. 32.8). Certain of the West Coast star- 

 fishes brood their eggs. In one very small species, the female carries her eggs in 

 clusters fastened to her mouth. Others arch the center of the body and draw 

 the arms together making a kind of brood pouch in which they hold the eggs. 



