(JASTRODES PARASITICUM KOROTNEFl''. 83 



free margin of the epidermis. This condition of the egg-cells recalls 

 much of that of the egg-cells of actiniae described and figured by 

 Hertwigs ('79). The authors give that the eggs in those forms arise in 

 the basal part of the mesenterial epithelium and become imbedded in the 

 mesogloea, but they keep connection with the surface of the epithelium 

 by means of a stalk- 1 ike process sent out from the egg-body, so that 

 the entire egg assumes a pyriform; further, the process shows longitudinal 

 striations. Thus the resemblance of the egg-cells in the two forms 

 is very close. 



Eggs showing an alveolar structure as in ordinary ctenophores 

 were not met with, in spite of the fact that the nucleus may be 

 nearly as large as that of mature eggs of ordinary ctenophores given 

 by previous writers. Thus, while the diameter of the nucleus of the 

 egg in the present form measures about 30;/, according to Chun ('80), 

 it measures in: Ba^oe 40 fi, Ccstus 35//, Enchlora 28 /i, Euchans 26 fx, 

 and Lampetia \iii respectively. I have also observed in the egg of 

 Coeloplana the diameter of the nucleus measured 20// on the average. 



Small individuals contain as a rule small egg-cells, and large ones 

 larger cells besides small. Thus the diameters of the nuclei of the 

 largest egg-cells contained by individuals of various sizes have measured : 

 Diameter of body (mm.). Diameters of egg-nuclei (z^'), 



0.15 7. 7. 7-5, 7-5- 



0.25 8, 8, 8, 7.5. 



0.3 14, II, II. 



0.35 12, II, 15. 



0.5 22, 19, 16. 



1.2 22, 22, 24, 24. 



1.4 26, 24, 24, 24. 



2.4 27, 30, 28, 30, 



2.5 28, 32, 30, 31. 



The egg-cells may be recognized in any stage mentioned above, 

 in fact even in the earliest developmental stage of the animal, when 

 the body is cylindrical as yet (PI. 8, fig. 9; ov). In the planula-stage 

 too, I was able to make out some cells apparently sexual. They lie 

 dispersed among the endodermal cells and may be distinguished from 

 the latter by the features that the cytoplasm appears much more 

 compact and the nucleus is somewhat larger in size. 



When the eggs are laid remains unknown, but probably soon after 

 the liberation of the parasite from the body of the host. Sometimes 



