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



Plasconia, Dilcpttis, and Paramecium aurclia. Neither, however, 

 appears to liave seen ovules in either of these Infusoria sufti- 

 ciently ilistinet to deseribe their composition in detail. 



Lastly, I would advert here to the rhizopodous forms which 

 Vortice/la occasionally appears to assume when under gemnn- 

 ])arous x'cproduction. Stein has described it in Acinetn, and I 

 have since observed it in a llhizopod undistinguishable from 

 Amn'ba Gleichenii ; I have also seen VorticelldE developed singly 

 from Aciru'ta ; and am now compelled to return to the conclusion 

 which I doubted formerly, viz. that the rhizopodous dc\'el()pnicnt 

 which takes place in Euglena is a similar ])assage of the nucleus, 

 and ])crhaps certain other contents of this Infusorium, into a 

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

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

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

 phosis iuto rhizopodous forms similar, but the sudden contractile 

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

 nearly the same as G, tahulatum) is so like that of Vorticclla^ 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 Tuuicata or Salpidai. 



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 Euglena 

 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 Eugbjpha, where also 

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

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

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

 ment, or as a reproductive gcmmiparous 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 devcloi)ment, like the rhizopodous cell of the Characcac, for it took 

 place in several Crumcnula;, which had respectively been enwrapped for a 

 short time iu 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. Ilist. vol. wii. p. 115), and since then I have returned to 

 the old view, which is that above ex])ressed; for independently of other 

 evidence in favour of it, Euylenu would be an excei)tiou to what now seems 

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

 considered this granular metamorphosis of the nucleus into polymorphic, 

 rhizopodous bodies, a foreign development. 



