240 HETEROGENETIC ORIGIN 



interesting and much-worked-at forms of life — the Ciliata — can 

 have such astounding and comparatively rapid modes of origin, 

 yet their origin in this way is, in reality, no more astonishing and 

 apparently incredible than the origin of Zoogloea masses from 

 aggregates of Bacteria, the fusion of such aggregates into in- 

 dividualised masses of matter, followed by repeated processes 

 of segmentation — ultimately resulting now in the production of 

 Fungus-germs, now of Monads, and now of Amoebae. 



Even if this last and final proof as to the actual mode of origin 

 of the Ciliates in filtered organic infusions had not been made out, 

 the other facts mentioned would have been, as I have said, almost 

 impossible to be explained satisfactorily, except on the supposition 

 that the Ciliates had been formed, in some manner, from the pellicle 

 itself. 



For if the first Ciliates that appear in infusions of hay or of 

 other plants came from the air or the water, there ought not to 

 be this constant association between the particular kind of Ciliate 

 found and the material from which the infusion has been derived. 

 And, again, if the forerunners of the Ciliates had passed through 

 the filter as invisible germs derived from air, water, or the plants 

 themselves, the Ciliates ought not to reveal themselves all at once 

 (or comparatively so) as organisms of full size. All sizes between 

 such hypothetical, invisible or minute germs and the full-sized 

 organisms ought to be forthcoming. They are, however, absent ; 

 and, as we have seen from the previous quotations, there is no 

 ground for supposing that any such minute germs or spores are 

 ever formed by Ciliated Infusoria. 



These difficulties taken together, as well as the others previously 

 referred to, would be incapable of being reconciled with the 

 facts, unless it could be shown that the Ciliates which first appear 

 are developed in and from the substance of the pellicle itself. 

 That being so, it becomes comparatively easy to understand 

 the reason of particular Ciliates always appearing in particular 

 infusions, and appearing, almost at once, nearly of full size. 



So much then concerning " the direct origin of Ciliates from the 

 pellicle " ; but, as I have already shown, that is not the only way 

 in which they arrive in organic infusions. We have also to bear 

 in mind what I have termed " the amosboid origin of Ciliates in 

 the pellicle." I am not altogether satisfied with this latter desig- 

 nation, and yet am unable at present to find a better phrase. All 



