The Animal Oryairistn + tnl its (term-Layers 60 



wlu-mii he proves the actual origin of the sex-cells from 

 the ciuiodenu. The only other positive result which I will 

 touch upon is that concerning the route and cause of 

 migration of the sex-cells from their place of origin to their 

 place of maturing. Goette denies that they have any single 

 road which is the same for all species, as contended by 

 \\Yismann. He affirms on the contrary, that at least four 

 paths are demonstrable, namely, the gastric endoderm ; the 

 liases of the pouches of the radial canal; the spadix ; and the 

 ectoderm of the mamibrium. The kernel of Goette's con- 

 clusion on this subject, as opposed to Weismann's is, as I 

 understand, that the sex-cells arise widely scattered in the 

 parts and tissues of the polypoid colony, and that the de- 

 velopment of the gonads or sex glands consists in large part 

 in the drawing together or concentration of these dissemi- 

 nated elements, in some cases into buds that are to become 

 medusa- proper, and in other cases where the medusoid is 

 whollv absent, into the gonophores or brood-sacs which arc 

 outgrowths on the polyps. The diversity of the place of 

 origin precludes the possibility of any single "germ track." 

 Again Goette does not believe, as Weismann does, that 



lu /journey ings of the sex-cells arc- due wholly to their own 

 independent activity, and considers the comparison of their 

 movements with those of migratory birds, and the ascrip- 



ion to them of an innate instinct, to be entirely fanciful. 

 He holds, on the contrary, that these cells are largely car- 

 riid along passively by forces which originate in the sur- 

 rounding tissues and structures. His observations on the 

 cells of I'orfocorync have, he says, been particularly con- 

 vincing that the wanderings are largely passive, and that 

 even where there is intrinsic movement this is indeterminate 

 as to direction, so that the final goal of the cells is in every 

 case determined chiefly by influences which lie outside Hu- 

 t-ells themselves. 



What the outside force is which Goette conceives to pro- 



