the i^onads has been supposed to afford means of descrimi- 

 nating between the sexes, the males differing from the fe- 

 males in the brigliter yellow of the gonadial tissue. But 

 this distinction aces not hold, and it is necessary to ex- 

 amine the individual medusae with a lens in order to sepa- 

 rate the sexes. The ovarian eq,g5, enclosed in the ectoderm 

 of the gonads of the female, give them a granular appear- 

 ance as contrasted with the more homogeneous and translu- 

 cent tissue of the male. When a large number of the jelly- 

 fish are separated into t-/o vessels, one containing the 

 males and the other the females, +he general color tone is, 

 it is true, brighter and more lively than that of the fe- 

 males. But the specimens in each dish range all the way 

 from light straw color up through orange, ochre, sienna, to 

 dark brown. 



III. EMBRYOLOGY . 



It is my purpose to give in outline the main 

 points in the early part of the life-history of Gonionema . 

 I have not discovered that this species exhibits any nota- 

 ble peculiarities. I shall lay greater emphasis upon cer- 

 tain features of the later developmental stages, which have 

 more significance in so far as they are less familiar. 



