236 Mr. H. J. Carter on the Organization of Infusoria. 



PIcesconia, Dileptus, and Paramecium aurelia. Neither, however, 

 appears to have seen ovules in either of these Infusoria suffi- 

 ciently distinet to describe their composition in detail. 



Lastly, I would advert here to the rhizopodous forms which 

 Vorticella occasionally appears to assume when under gemmi- 

 parous reproduction. Stein has described it in Acineta, and I 

 have since observed it in a Rhizopod undistinguishable from 

 Amoeba Gleichenii ; I have also seen Vorticella developed singly 

 from Acineta ; and am now compelled to return to the conclusion 

 which I doubted formerly, viz. that the rhizopodous development 

 which takes place in Euglena is a similar passage of the nucleus, 

 and perhaps certain other contents of this Infusorium, into a 

 rhizopodous form*. It appears to be as general in the family of 

 Euglena as in that of Vorticella ; and although these two organ- 

 isms at first look very different, yet not only is their metamor- 

 phosis into rhizopodous forms similar, but the sudden contractile 

 movement at intervals of a species of Glenodinium (Ehr., very 

 nearly the same as G. tabulatum) is so like that of Vorticella, and 

 Glenodinium is so closely allied to Euglena, that we cannot help 

 seeing in this act alone a feature which links together Euglena 

 and Vorticella, — if not also, with other points of resemblance, 

 the biphorous Tunicata or Salpidse. 



Hence then, as Vorticella may pass into Acineta or Amoeba, 

 and Euglena also into a rhizopodous cell, and the former may in 

 its metamorphosis produce young Vorticella, so perhaps Euglence 

 may produce young Euglence after a similar manner. 



How, then, are we to regard this granulating development of 

 the nucleus ? We have seen that it occurs in Euglypha, where also 

 there is a distinct development of ovules. Are we to regard it 

 as the flowering of a dioecious male plant, or as the budding of a 

 monoecious or bisexual flowering one, — as the impregnating ele- 

 ment, or as a reproductive gemmiparous one ? We can hardly 

 consider it budding or gemmiparous, because it is a development 

 of the nucleus itself, which allies it more to fissiparous or dupli- 

 cative subdivision ; and if this cannot be determined, perhaps it 



* This was the original view I took of it. I then conceived it to be a 

 foreign development, like the rhizopodous cell of the Characeaj, for it took 

 place in several CrumenulcB, which had respectively been enwrapped for a 

 short time in rhizopodous cells, when I thought the germs of the new de- 

 velopment might have been introduced into them. Still I wavered in my 

 opinion, as may be seen in the latter part of my description of this (Ann. 

 and Mag. Nat. Hist. vol. xvii. p. 115), and since then I have returned to 

 the old view, which is that ahove expressed ; for independently of other 

 evidence in favour of it, Euglena would be an exception to what now seems 

 to be a general occurrence in organisms closely allied to it, that is, if we 

 considered this granular metamorphosis of the nucleus into polymorphic, 

 rhizopodous bodies, a foreign development. 



