652 



WHITMAN. 



[Vol. VIII. 



cell, while in Stentor a whole crown of such organs is formed 

 without any division into cells. Could one ask for a clearer 

 demonstration } Are we not forced to conclude with Gruber 

 that ^^ however great the difference between an uifusorinm and a 

 highly organized animal, it canjiot be a qualitative one. We 

 can assume that the satne vital elements serve in both as the 

 foundation, only in ever neiv combinations. This kinship 

 declares itself very clearly in the con-espondence of 7nany organs 

 of the infiisoria with those of the higher organisms" {I.e. p. r6). 



C(^ 



Fig. 3. — A, "Corner cell" of Cyclas cornea. B, Section of three cells. Other 



letters as in Fig. 2. 



" So finden wir," says Gruber, " in einem Thiere, das 

 schon hoch auf der Stufenleiter der vielzelligen Organismen 

 steht, dieselben Grundelemente wieder wie in dem einzelligen 

 Infusionsthierchen. . . . 



" Wieder und wieder der Beweis von dem gottlich einfachen 

 aber auch gottlich gewaltigen Gesetze der Einheit der Natnr" 

 (p. 18). 



The entoderm of Dicyema illustrates one or two points of interest in this 

 connection. We have here an organ in which, as often happens, in parasitic 

 degradation, cell-formation has been dispensed with. The entoderm remains 

 throughout life as a single cell, and the whole process of reproduction, for both 

 kinds of embryos, is carried on in the body of this cell without any cellular organs 

 whatever. 



In one respect this unicellular organ, which was undoubtedly once multicellular, 



