i\Ir. II. J. Carter on the Organization of Infusoria. 239 



surface of the plasmic zone, thus under an arrest of develop- 

 ment, indicate that it has taken this sliape from consisting ori- 

 ginally of a number of ovules enclosed within a globular mem- 

 brane ; and if so, is the passage of the granules of the nucleus 

 into them to be considered an act of impregnation ? If they 

 were ovules, then one would think that there would be no oc- 

 casion to lay up extraneous nutrition for them, more than in 

 Eugh/pha, Spongilla, &c., the ovules of which, after the parent 

 perishes, remain for a certain time in the effete bod)^ and 

 ultimately undergo a kind of incubation generally after they 

 have left the cavity in which they were developed. Again, 

 though very much like the granulating of the nucleus in Eughj- 

 pha and Amoeba, where the bodies which are thus evolved singly 

 or in groups generally become endowed with active locomotive 

 power before they leave the parent; yet in these instances no 

 plasmic zone around the nucleus preparatory to this has been 

 observed*. In the present stage of our knowledge, therefore, 

 we are not able to say whether this be a gemmiparous or a 

 generative process ; whether monads developed in this way are 

 merely multiplied zoosperms of this organism, or the mixed pro- 

 duct of a genuine generative process ; whether there be, in ad- 

 dition, an ovular development, as in Eugh/pha, &c. ; or whether 

 the monads thus developed soon perish, or become new cells. 

 Certainly in Spongilla there are two kinds of developments, viz. 

 the so-called zoospores or monads, and the transformation of the 

 ovules directly into the sponge-cell : both are polymorphic, and 

 at first have each (?) a single cilium ; but one being much smaller 

 than the other, they may perhaps be regarded respectively as 

 macrogonidia and microgonidia, as Braun has suggested'for the 

 zoospores of Hydrodicti/on\. From whence, then, come the so- 

 called zoospores in the latter — from the granules or the nucleus ? 



Lastly, there are two organs in those Euglenoi (mihi, which 

 for no just reason Dujardin has separated from this family), viz. 

 Phacus (Ehr.) and Crumenula texta (Duj.), that I should notice 

 here, though I am perfectly ignorant of their use. These are 

 the so-called " red spot," which in Crumenula texta, where it is 

 comparatively very large, rests in the form of a small obtuse 

 cone upon the vesicula ; and the glairy capsuled body, which 

 always exists in the centre of Phacus, and in the long lip of 

 Crumenula teita, &c. ; — in some Euglena there is an undefined 

 yellowish body here. 



Of what use the "red spot" or body may be, I am igno- 

 rant ; but it is very common to see matter like that of which 



* Actinophrys oculata (Stein), however, ])rcscnts a nucleus and plasmic 

 zone of this kind. (See p. 22S.) 



t Rav Soc. Pub. Bot. and Plus. Mems. he. cit. 



