iLies of the adult, and the rhopalia to be new structures. 

 While Glaus, on the other hand, maintains that in Aurelia the 

 entodenn is formed by invagination, the septal funnels have no- 

 thing to do with the subgenital cavities, and the rhopalia are 

 then developed in the basal portion of tentacles. 



These persistent differences of opinion made it desirable 

 that a third person should review the whole subject, and for 

 this reason I was very anxious to obtain developing eggs and to 

 rear the larvae of Gassiopea. I failed to obtain the eggs 

 and, therefore, cannot touch upon the question of the origin 

 of the entodei-m or of the relation of the early scyphistoma 

 to the actinians. But I did succeed in rearing scyphisto- 

 mas from plar.ula-like buds and was able to study larvae of 

 nearly all stages from the bud to the fully formed medusa. 

 It may be objected that as the larvae that I studied were pro- 

 bably all produced by budding they can furnish no evidence as 

 to the course of development of egg embryos. The validity of 

 this objection depends, it seems to me, upon the manner in 

 which the bud is formed. In the case of the fission of an 

 Actinian, naturally, neither of the two nev/ individuals passes 

 through any lai'val stage, nor would one expect a hydroid stage 

 in a medusa bud that is produced directly on the body of a 

 medusa, althoi:^gh one such case has been described. Again, it 



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