OF THE PEOTOZOA. CILIATA. 335 



Van der Hoe v en and others, yet it has latterly found two advocates in Prof* 

 Perty and Mr. Carter. The latter writer (A. N. H. 1856, xviii. p. 225) can 

 adduce little direct e\^dence to support his views, and seems to rest more 

 weight upon argument from analogy with Amoehcea, ArceWma, Astasias, and 

 Euglence, in all wliich he has satisfied his own mind of the presence of ovules, 

 and of their development in the two latter genera. "The same kind of develop- 

 ment," he writes, " of the ovule probably takes place in aU the Ehizopoda as 

 in Sjjongilla and in Astasia and Euglena :" but this is not proving that Hhi- 

 zopoda are developed by ova ; and the entire value of the presumed analogy 

 ^vith Astasice depends on our admitting a natural afiinity and close similarity 

 in organization between that family and Ciliated Protozoa, on the one hand, 

 and Rhizopodous Protozoa on the other. Indeed, we imagine the prevailing 

 opinion to be, that the histoiy of development of Asfasicea corresponds rather 

 with that of vegetable organisms than with that of the Protozoa ; for this so- 

 called ovular rej)roduction of the Astasiwa certainly seems analogous with the 

 development of zoospores in many unicellular Algae. 



To recur to Mr. Carter's statements, he tells us he applies the term 

 " ovules " to " a number of discoid or globular nucleated cells, which appear 

 together in the sarcode of some of the Infusoria ; " and he subsequently pro- 

 ceeds to uphold his views by his own personal observations, and by inferences 

 drawn from others. " In many of Ehrenberg's enterodelous Infusoria it is 

 not uncommon to see a number of defined globular bodies, of nearly equal 

 size and of a faint opaque yellow colour, which closely resemble ovules — 

 e. g. Amjjhileptus fasciola (Ehr.), Himantophorus Charon (Ehr.), &c. ; nor is 

 it improbable that many of his Trachehna, which come near Planaria, possess 

 ovules similar to those which are found in the latter ; but, from beuig so much 

 mixed up with the spherical cells, pass equally unnoticed while in, as well as 

 when out of, the body, under such circumstances. M. J. Haime, however, has 

 distinctly seen instances in wliich these bodies have been ejected from Infusoria, 

 and have passed into locomotive animalcules under his eye. Thus he states 

 that in Plcesconia they form a group of from forty to fifty in the middle of 

 the body, are round, issue one by one, remain tranquil some time, then deve- 

 lop two filaments, one in front, the other behind, and move about rapidly. 

 In an ' undescribed ' species of Dileptus they are whitish, and form a wreath 

 extending almost throughout the whole length of the body, become yellow 

 towards the anal extremity, where they pass out with the remains of the 

 food, soon develope two opposite filaments, and move about rapidly. In 

 Paramecium Aurelia, M. Haime states that an ovary appears some hours 

 before death, about the middle of the body, which becomes filled with about 

 sixty little nuclei : these increase in size, burst the ovisac, and thus pass into 

 the body of the parent, from which they finally escape by an opening in the 

 tegumentary covering, formed by the diffluence of the latter ; and the ovisac 

 follows them." 



Perty has used great diligence in searching for the presence of ovules or, 

 more accurately, of germs (Blastien), and has adduced various arguments for 

 their existence. He states {op. cit. p. 6Q) that their aspect is distinctive, 

 although their colour varies in difiPerent species, that, imlike food, they re- 

 tain their form, increasing only in size, and that, on the dissolution or breaking 

 up of the animalcules, they display themselves as free individualized struc- 

 tures. It is only, he adds, in incomplete forms, in young and imperfect beings, 

 that any doubt can exist respecting the character of these corpuscles. Ovular 

 development does not take place as Dujardin siu'mised, by detached morsels 

 of the sarcode, nor by ova such as Ehrenberg supposed, but by a peculiar 

 set of bodies, originating in the interior of the animals, and progressively 



