146 Dr. O. Zacliarias on the Reproduction and 



(and therefore allied to the Acinetina and Opalina), which my 

 description of the egg-like structure in the body-cavity of 

 Rotifer vulgaris suited most exactly. Prof, von Stein was 

 now consulted with regard to the present case, and he had the 

 kindness to compare my representation with his own previous 

 observations. From this it became exceedingly probable that 

 I had again met with the same parasite which Prof, von 

 Stein had formerly discovered and described under the name 

 of Trypanococcus rotiferorum. 



Prof, von Stein, in the discourse which he delivered before 

 the above-mentioned meeting of naturalists, made very detailed 

 statements upon the organization of Rotifer and the structure 

 of Trypanococcus, but unfortunately he did not prepare a 

 report upon it for the ' Tageblatt.' This explains why 

 Trypanococcus is not so well known as it certainly deserves 

 to be. 



What I regarded as a cavity (vacuole) filled with sperma- 

 tozoids in the supposed " Ggg,^ is, according to Stein, the 

 body-cavity of the parasite, which is lined with delicate, 

 constantly vibrating cilia. From this body-cavity a canal 

 (oesophagus) is supposed to go to the repeatedly-mentioned 

 micropyioid aperture, which then would acquire the signifi- 

 cance of a mouth. Upon this, however, I have to remark 

 that I have never observed the presence of such an oesophagus 

 even when employing the oil-immersion lens. If I had 

 recognized any canal of the kind I should hardly have arrived 

 at the notion that the structures in question were to be inter- 

 preted as " eggs." On the other hand, I must admit that a 

 stomach with cilia on its inner wall very well explains the 

 visual impression which I referred to a vacuole rilled with 

 swarming filaments. The globular structure in the vesicle 

 of Trypanococcus is regarded by Stein as the nucleus of the 

 Infusorial parasite. 



The question now arises, however, as to what is represented 

 by the saccules, the presence of which I have quite indubi- 

 tably ascertained, and in which I was able to detect such 

 peculiar phenomena of contraction with formation of vacuoles. 

 Prof, von Stein declares that he never saw such sacciform 

 appendages upon his Rotifers; but he is of opinion that they 

 may very well be interpreted as a phenomenon of reproduc- 

 tion. Possibly a ciliated offshoot may be produced by gem- 

 mation, from which, finally, the motionless and parasitic 

 Trypanococcus-\ esicle proceeds. It is unfortunate that Prof, 

 von Stein has no facts relating to the actual course of such a 

 bud-formation, and that, in consequence, we can here proceed 

 only upon hypothetical grounds. It was precisely these sac- 



