234 ON THE ORGANIZATION OF THE GENUS GREGAHINA OF DUFOUR. 



Besides, observing that the peculiarity of the movements is more like that of animals than 

 of plants, he finally states, that the habitation of the Grqgarinae is such as is frequent 

 among lower animals, and but seldom among plants. 



Without at all entering into the views of Henle, in considering the Grcgnrinw of a 

 veg^able nature, I must state in opposition to Kolliker, that contractility of cell membrane 

 does exist in the vegetable kingdom, if the Achhja prolifcra be regarded as a plant, for its 

 spores after escaping from the sporangium do not only move by means of vibrilla?, but 

 there is also a very evident degree of contractile movement existing in their membrane. 

 In relation to the habitation of plants being but rare in animals, my observations lead me 

 to consider the occurrence of plants growing within healthy living animals as by no means 

 an unfrequent one.* 



In answer to a second question proposed by the author, "Sind die Gregarinen einzellige 

 Thiere?" (Are the Gregarime single-celled animals?), he regards the integument of these 

 animals as cell membrane, the fluid and granular matter within as cell contents, and the 

 clear corpuscle, among the latter, as a cell nucleus containing a nucleolus. This is the 

 most important opinion as to the character of the parasite, and is the one most objected to 

 by Ilenle and Frantzius, who contend that the interior corpuscle is not of the nature of a 

 cell nucleus. 



Kolliker appears to have been mostly influenced in forming an idea as to the nature of 

 the Gregarina, from its close relationship to the Monocystis. The division of the contents 

 in the two parts of the body he regards as not being a particular membranous partition, 

 but consisting of the same clear, tough fluid, which binds the granules of the contents 

 togcther.t 



The proboscidiform appendage possessed by many species, the author considers as no 

 objection to the simple cell nature of the animal, and as instances of similar cells, refers 

 to the pollen granule, among plants, which often has prolonged growths, (AitswucJisc,) and 

 the capillaries of the larva of frogs in the course of development, among animals, which 

 then have prolonged solid growths of the cell membrane. 



Frantzius, in some concluding remarks upon Grcgarinsc, in the Archivfur Naturgcscluclrfc, 

 for 1848, p. 190, remarks, that the partition separating the contents of the animal into 

 two parts, he does not consider, with Kolliker, as a thickened layer of 4hc fluid of the 

 body, but, with Stein, thinks it is a partition from the general integuments of the body, 

 which, he continues, is perhaps foreign to the conception of the true cell.;}: 



Kolliker is so satisfied of the simple cell character of the parasite that in the second 

 vol. of the Zcitschrift far Whscnschaftliclic Zoologic, p. 114, he observes, hardly any body 

 will doubt the Grcgarinx, with their structureless membrane, simple contents, and nucleus, 

 arc in the highest degree like a common cell. 



My observations on the genus Gregarina of Dufour, lead me to consider it as occupying 

 a much higher position among helminths than has been generally attributed to it, and with 

 Frantzius, Stein, and Ilenle, as not being a simple organic cell. 



* See Proc. Acad. Nat. Sci. vols. 4, 5. t Lop. cit. p. 22. 



} Die in den Gregarinen vorkommende Srheidcvvand, die ich nieht vie Kolliker nur fur ein verdickte Schichte des 

 fliissigen KOrper-inhalts, somlcrn mit Stein obenso wio die ilbrige K6rperhulle fur cine Mcmbran halte, ist einmal etwa 

 !ciii Begriff der wahren Zelle Fremdartiges. 



