of which has its root-springs in an experience as 

 old as the human race . . . 



II 



But in my appraisal of the Ctenophores, I do 

 not neglect to note some other details that manifest 

 themselves in the case of the moon-jellies. Among 

 the different sexes, I distinguish a number of 

 gravid females. The sexes are easily differentiated 

 at a glance : the males having gonads of a pinkish 

 cast, while these horseshoe-shaped organs in the 

 female are a bright yellow. Careful scrutiny dis- 

 closes that the maternal pouches of the females are 

 filled with eggs while the folds of the veil-like 

 appendages around the central mouth are clotted 

 with masses of minute bodies apparently different 

 in structure but of the same cast as the eggs. It is 

 later that I learn that these latter are the planulae, 

 or larval bodies only slightly advanced in develop- 

 ment from the egg stage. Here, then, is an oppor- 

 tunity. Here to hand is an abundance of material 

 such as I most desire for the purpose of extending 

 a research into the life history of Aurelia. 



My first-hand acquaintance with the moon- jelly 

 has been slight. All my attempts to penetrate the 



[363] 



