40 T. Kf)MAI: STUDIES OX T\Y() ABERRANT CTENOPHORES 



to tlie nature of the invaginations. Indee'd, Hertwio himself seems to 

 be rather skeptical on this latter point and he has acknowledged the 

 possibility of attributing to those structures some unknown sensor}' 

 function ('8o). Now, the seminal receptacles of Coeloplana described 

 above recall much of the structures under discussion. Roth are flask-like 

 invaginations from the dorsal epidermis which are situated along each 

 meridional canal in approximate numbers, the receptacles four to thirteen, 

 the ' Sackchen ' six to seven. Discrepancy may be found only in the 

 character of the cells that line the blind end of the invaginations, these 

 cells being flattened in the receptacles and cylindrical in the Sackchen. 

 In view of the facts given above, we are very likely to be justified in 

 drawing a homology between the two kinds of invaginations, and if so, 

 the observation that the invagination functions as the seminal receptacle 

 in Coeloplana appears to throw some light on the question on the 

 function of that structure in Callianira. 



I have also often met with a structure that resembles closely what 

 has been described by Hertwic; from the cydippids under the name of 

 'Verbindungsstrang'. That is a tract of cells stretching between the 

 epidermis and the ovarial membrane, and shows sometimes a tubular 

 structure (PI. 5, fig. 7, c. si), but appears at other times as a solid 

 strand of cells (tig. 5; c. si). Further, it is not uncommon that, it 

 terminates freely in the body parenchyme without reaching the epidermis, 

 which fact shows clearly that the tract develops from the ovary and 

 not from the epidermis. Apparently the tract has nothing to do with 

 the origin of the sexual cells nor with seminal receptacles. Perhaps, it 

 is morphologically homologous with the sperm-duct, but it is certain 

 that the tract does not serve as an oviduct, as the eggs always fall into 

 the lumen of the canal and are laid through the mouth aperture. 



Lastly, the space found in the testicular cavity. ' Genitalsinus ' of 

 previous writers, arises evidently in correlation with the development of 

 spermatozoa in that cavity, and it is never found in the testes which 

 have developed no spermatozoa as yet. According to Chun ('92), the 

 space communicates with the cavity of the canal in certain cydippids, 

 hut I could not find such a feature in the present form. 



Krhmpf ('20, '21) holds an opinion entirely at variance with me 

 concerning the nature of the invaginations that are found along the 

 ovarial tracts. Indeed, one of the greatest discrepancies between the 

 results of his work and mine may be said to lie in this point. Whereas 

 T have attributed to the invaginations the function of sperm-receptacles. 



