440 •^- " FÜIJ.ARTON, 



ailvauced stages, stands out in relief from the cell contents, Figs. 31a, 

 32 p. The deutoplasni, which in younger oosphères, Fig. 28, 29 deut, 

 is fairly ecjually distributed throughout the micromere, becomes more 

 aggregated in older forms, Fig. 31, 32, and the portion towards the 

 periphery contains more protoplasm. Fig. 31, 31a, 32 pr. This may 

 be an indication of approaching macromeral division which, however, 

 was not exhibited in the oldest generative products found in the body- 

 cavity. 



My observations are in accord, so far as development to the ripe 

 »tvum is concerned, with that outlined by Leuckakt A: Pagenstechek, 

 who figure (tab. 20, fig. 4) two stages to the ripe egg, the first being 

 one large and two smaller cells , and the second and more advanced 

 being one large and one smaller cell. Keferstein gives another 

 explanation as to the course of development , and describes what I 

 have called segmentation stages in these words : "Bei einem Eier- 

 haufen mit solchem reifen Ei erscheinen die übrigen Eier nur wie 

 ein kleiner Anhang an diesem grossen" (tab. 9, fig. 5). 



From his figure it may appear that his "Eierhaufen" corresponds 

 to my oosphère and that his "kleiner Anhang", although composed of 

 cells unlike one another, might represent the micromeral elements 

 which I observed. Unfortunately he gives only one figure, so I am 

 unable to say whether my suggestion as to correspondence is accurate, 

 or whether his would be comparable to some of the stages in my 

 investigation previous to the egg attaining ripeness. If what I have 

 described as micromeres of the oosphère were simply "kleiner An- 

 hang"', we should expect to find that there was no common cell wall 

 between the large cell and one of the smaller cells, or between ad- 

 joining small cells, and no polar body would be found. But in my 

 specimens there are common walls, not two walls, and a polar body 

 is distinctly seen in several. I therefore conclude that there are two 

 classes of multicellular generative products, one kind preceding the 

 attainment of ripening of the egg, and the other subsequent to ferti- 

 lisation. 



The female genital orifices, Fig. 35 /.o., are two pairs of 

 transverse slits immediately in front of the nerves (nv) given ofi' from 

 the ventral chord to the fourth and fifth pairs of i)arai)odia, par. IV, V. 

 They are situated on the ventral aspect of the body and , in fully 

 ripe females, are connected to the sides of the body at the angle 

 formed by the i)ody and the anterior surface of the fourth and fifth 

 l)arapodia. Leuukart it Pagenbtecher saw in 1858 these oi)enings 



