Dr Barry on Fissiparous Generation. 219 



Volvox. And it is not improbable that, revolving as no doubt 

 the essential part of the mammiferous ovum for a short period 

 does,* it revolves by means similar to those which produce the 

 rotations of the Volvox. 



71. There really seems to have been much truth in the re- 

 mark long since made by Oken, that the larger animals are 

 formed of bodies comparable to the Infusoria. The cell itself 

 is a little organism, and cells coalesce to form a larger one. 



72. The remarks made in this memoir respecting fissiparous 

 generation, are of course intended to apply also to gemmipa- 

 rous reproduction, or propagation by means of buds.t 



73. Tfie so-called " Spontaneous Generation,''^ — Parasites. 

 How do animalcules and vegetable productions arise in the 

 infusions of organic matter I I venture to believe they may 

 have their origin in those particles (of hyaline) which I have 

 called the true cell-germs (par. 16.) These cell-germs, as 

 part of the animal, or vegetable organism — for instance, in 

 the elaborated liquor sanguinis (par. 34), or the descending 

 sap — would have been developed according to the stimulus re- 

 ceived within that organism ; but now set free, each becomes 

 developed into an independent organism, capable of propagat- 

 ing itself, and producing a like form, which it does in a variety 

 of ways. 



74. Is not this the mode of origin also of the Entozoa, and 

 of all parasitic growths % If cell-germs become developed after 

 they have left an organism, they may surely lead an indepen- 

 dent (though parasitic) life within it, — become developed into 

 various forms, — and propagate their species. J 



75. It is known that the various organisms, and even organs, 

 have their peculiar parasites. If the view just mentioned be 

 admitted, this is no other than what we should expect, from 



* Professor Bischoflf of Heidelberg, on seeing the description given by myself 

 (Phil. Trans. 1839, p. 355) of the " Rotatory motions of a mulberry-like object 

 in vesicles under the raucous membrane of the uterus" in the Rabbit, forthwith 

 proceeded to an examination of the ova of this animal as they lay in the ovxducty 

 and found what he calls the " yelk" in a revolving state : the rotations being 

 produced by cilia. (Miiller's Archiv, 1841, Heft 1). 



t Both attached and separated, 



+ I found in the blood of a heart that had been kept for several days, moving 

 t;»6rio-like bodies, which appeared to have been derived from the nuclei of cor- 

 puscles of the blood ; and in what was apparently an ovum, escaped into the Fal- 



