64 The Unity of the Organism 



vious formulations, sets up a number of hypotheses. That 

 these are fully proved is not contended even by Weismann 

 himself: they are only given a good degree of -plausibility 

 or probability. Then comes another investigator of equal 

 competency who goes over essentially the same ground and 

 reaches essentially the same factual results, but who does not 

 believe the hypotheses propounded by the first investigator 

 are supported by the facts. What can a third person legiti- 

 mately see in the total situation other than that whatever 

 probability was given the hypotheses by the one investigator 

 has been taken away from them by the other investigator? 

 So far as we have yet gone with our examination we are, I 

 think, compelled to recognize that as regards interpretation 

 of structure and reproduction in the hydromedusae, Goette's 

 work leaves the matter just where it was before Weismann 

 propounded his hypothesis. But we have not concluded the 

 inspection ; we have only considered Goette's work in its re- 

 futational or destructive aspect. Whatever of positive re- 

 sults both as to observation and hypothesis he has to set 

 over against Weismann's must now be briefly considered. 

 And here we return to the matter in hand in this section, 

 that, namely, of the relation of the sex-cells to the germ- 

 layers. 



Goette believes he has proved incontestably that the sex- 

 cells do arise in the endoderm in some species, so that Weis- 

 mann's assertion that in this group they always arise in the 

 ectoderm is wrong. But of far greater importance, Goette 

 shows that not only the endodermal but also the ectodermal 

 origin of the sex-cells is such as not to give the least warrant 

 for the hypothesis that any part of the cell (the supposed 

 germ plasm being of course aimed at) does not arise by trans- 

 formation of the material of the layer in which they first 

 appear. And in this it seems to me he has made his case. 

 His description accompanied by numerous drawings of the 

 sex-cells in Corydendrium parasiticum, may be instanced 



