n 



498 



THE BEGINNINGS OF LIFE. 



our knowledge 



increases con- 



Ptesconia may fairly be supposed to have emerged frorn 

 the empty cysts ^ 



And again^ the same independent reasons which tend 

 to countenance the observations of M. Pineau also lend 

 support to those of M. Haime and Mr. Carter. Not 

 only may apparently similar vegetal vesicles be trans* 

 formed now into Vorticelte and now into Oxytrichigj 

 but J as we have seen (p. 468), others of them may be 

 converted into the characteristic form of Plsesconia. 



Other cases of such transformations will doubtless soon 

 be made out by subsequent observers^ and in addition, the 

 altogether artificial distinctions now supposed to exist 

 between many of the forms of Ciliated Infusoria are 



r 



likely to disappear as 



their more habitual developmental phases. 



suspected that certain 

 as belonging to distinct 

 genera, are really only transitional states of other 

 forms^ which may pass into one another quite gradually 

 without an intervening stage of encystment. A trans- 

 formation of Vorticellx into Oxytrichse without previous 

 encystment^ has been described by Mr. T. C. Hildgard '^ ; 

 whilst I have also seen Paramecia derived from the 

 pellicle gradually assume the characters of Nassute I 



^ There was all the less chance of a mixture of the two Infusoria 

 having taken place originally, because the vessel, in which thousands 

 of the Keron<e existed and from which the encysted specimens were 

 taken, did not appear to contain a single specimen of Plxsconia Charon. 



2 ' Monthly Microsc. Journ.,' Nov. 1871, p. 232, 



' See p. 250. 



cernmg 



have long 



Systematic writers 



' species/ usually described 



coBcerning the 

 ttottbeymay 



vAn 



as 



? 



ifise 



from thi 

 or vegel 



else from p 

 ntlj individi 

 foiraations of 

 Ciliated Infus 

 times they oi 



ce 



m 



os^s int 



fo^"is ultimate 



1 



I 



lain 



upon tl 



™«er of whi, 

 '5'iability of 



e 



'^f con 



■^traordin; 



\ 



tlfllS 



s 





Mop 



^rau 



jOUt: 



