DISTOMUM ILEMATOBIUM. 231 



eggs. These were also found by Bilharz, bat only once, in the 

 interior of the oviduct of the female, the further course of which 

 contained ordinary eggs. The excrescence was conical, and 

 placed on one side, near to the more obtuse extremity, and 

 was situated on the above-described sharp margin. In these 

 structures, in which Bilharz only found a few small bodies accu- 

 mulated towards the process, Griesinger discovered living crea- 

 tures on the 29th of March, 1852. These moved by contractions 

 and extensions, until the thin shell, which Bilharz says was 

 clothed on the inside with a (vitelline) membrane, suddenly 

 tore, and the animal slowly crept out. For many hours it 

 underwent several changes of form by elongation of the neck, but 

 was then lost in the intestinal mucus. The figure given by 

 Griesinger exhibits distinct cilia, the presence of which, according 

 to Bilharz, at first was doubtful, until, in the summer of 1852, he 

 also recognised the same cilia distinctly. According to the latter, 

 these embryos were in nowise distinguishable from the true embryos 

 already mentioned. Griesinger also saw similar animals living 

 free in the intestine. On the addition of a large quantity of 

 water their movements ceased ; and, to speak zoologically, they 

 gradually acquired a different form, with escape of sarcode 

 globules or drops. Once Bilharz observed positively, that a 

 body of this kind, furnished with a process, reached the interior 

 of a vessel. 



Bilharz now thinks, according to his last communications, that 

 these capsules which occur in the liver, in the mucous membrane 

 of the bladder, and in the ureters, remain after the evacuation of 

 their embryos, becoming partly enveloped by calcareous deposits, 

 and partly filled with calcareous matter, in the same way as the 

 empty egg-shells themselves, and give rise to the process shortly 

 to be described. According to Bilharz, however, when situated 

 upon the mucous membrane of the intestine they are much 

 more completely got rid of. 



In explanation of these structures, to which Griesinger 

 paid particular attention, Bilharz expressed himself pretty de- 

 cidedly in the appendix to his first communications, to the effect 

 that they are not true eggs, although he once found one of these 

 capsules furnished with a spine quite in the anterior part of the 

 oviduct of a female, but probably a higher grade of development, 

 such as a sort of pupa-case of the animal already escaped from 

 the egg. Subsequently he thought that these capsules pro- 



