400 



over the ground several times and propose to publish elsewhere the 

 evidence which leads me still to maintain my former position. 



Here the question will be considered very briefly, and only in so 

 far as my observations and conclusions contradict those of my present 

 critic. 



Dr. Wheeler has studied what Nansen termed the »problema- 

 tical organsK of Mijzostoma , and is led to confirm the latter author's 

 supposition as to their ovarial nature. He goes further than Nansen, 

 for he states that all previous observers, Lovén, Semper, v. Graff, 

 Nansen, Proudho and myself, were in error in assigning an ovarial 

 character to the peritoneal epithelium of the body-cavity , and he in- 

 sists that the » problematical organs « are the only true ovaries of My- 

 zostoma. Moreover finding, with Nans en, similar »problematical 

 organs« in what I termed , and still describe as, the dwarf males of M. 

 glabrum he concludes that these so-called males are merely young her- 

 maphrodites, as von Graff originally supposed. This conclusion is, 

 however, unsupported by any evidence that the «problematical organs« 

 in the »males« ever give rise to ova — or to anything else ! 



The »problematical organs« are known to me form Nans en' s 

 description, but neither before nor since the publication of Dr. Whee- 

 ler's note have I been able to satisfy myself that they function as 

 ovaries in the hermaphrodites. I have recently examined several fresh 

 series of sections of specimens in which proliferating ovaries might 

 have been expected to be present, and have also worked over all my 

 old sections of 1884, but in none can I find evidence of the conversion 

 of cells of the »problematical organs« into ova. Like Nansen I have 

 seen large egg-cells embedded in or lying on the outer cells of the 

 organs in question, but failed to detect any stages in the organ in- 

 termediate between such cells and the small deeply-staining cells of 

 the organ itself. 



So much in justification of myself and other previous observers. 

 Unless Dr. Wheeler can produce strong evidence to the contrary, 

 I certainly incline to the opinion that Nansen may have been in the 

 right in believing his »problematical organs« to be rudimentary or ve- 

 stigial. Whether male or female in character is beside the question, 

 for an ovary or testis can only be known by its products. 



My mind is quite open on the point at issue, and it does not affect 

 my argument in the least whichever view be the right oue. I have 

 no wish to challenge Dr. Wheeler's positive statement that in the 

 hermaphrodites these organs are ovaries, but Avhen he insists that 

 they are »the only true ovaries« agreement is out of question. 



In another place it would be shown that ova are present in , and 



