Ore 



It 



IS 



nor 



e. 



\ 





' »s, he beH 

 Infus 



oria. 



e\ 



eves, 



Geiioti 



^^ Of the family 

 ^it that Ackk 

 ^*^'rior similar to 

 ■nd some others 

 nverted into /la'rtlt: 



rive rise to 



> 



■!il 



,1 



sen'ations ' on one Ou 

 positive to entitled: 



J cimla is 



formed, 



s 

 e 



ind a 



APPENDIX D. 



xcv 



ditions, in the precise nature of the developmental changes 

 or transformations observable amongst these organisms. In 

 fact, Stein himself has described a second mode of origin of 

 embryos within Acinetce of Vorticella origin. Such Acineice 

 did not possess the ordinary tentacles, though they presented 

 one or two short, closed, tubular processes projecting 

 anteriorly. Within, there was no longer the usual granular 

 contents with a nucleus and contractile vesicle : there were 



instead, six oval, cell-like bodies, about 



50 



in length, which 



seemed to have been developed out of the original con- 

 tents of the Acineta. These bodies were sharply defined, 

 and contained a coarse granular substance with a contractile 

 vesicle. In one of them a ciliated furrow was observed, 

 owing to the presence of which it more closely resembled 

 the usual solitary embryo of the Acineta. Such a multiple 

 development seems to be only an occasional modification 

 of the reproductive process. 



A glance at the other modes of reproduction which have 

 been described amongst the Ciliated Infusoria will astonish 



/ 



\^t AcmlH'MS^ the reader by their diversity, and will almost force him to 



come to the conclusion that there is no definite method 



do not, of course, *| of reproduction for any one species. There seem to be, 

 4 1 ///^/J-eroK^'" H ^^ther, different developmental possibilities by any one of 



Xor0^<f 1 



reallj 



lid only 



to assume, ^vhat 



.g in au ,., 



conC 

 to 



different ° 



the 



of ^' 



^ 





i 



which the reproduction of individuals may be brought about, 

 though the particular mode which is likely to occur on any 

 given occasion appears at present to be wholly uncertain, 

 ^ut the actual process gone through — although oftentimes 

 apparently the work of chance— would doubtless be capable 

 oi predication, if we knew what were the molecular forces at 

 work in organisms of difi^erent kinds, of different sizes, and 

 of different ages, and as well the degree and nature of the 

 modifying influence exercised by the ever-varying sets of 

 conditions to which these different organisms are subjected, 

 ^nder all their widely differing states of molecular activity. 



\ 



VOL. IT. 



g 



