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



it is coni])ns('d nuiltijilicd tlirougliout the body of Emjlrnn, both 

 in an aMiori)hous and nioli-cnlar lorni, or, wlicn nothing but 

 the ovules remain in the colourk\ss, transparent, iibrous eells of 

 the two sj)eeies mentioned, to see little granules of it moving 

 with a more than Brownonian motion among the ovules. Ehren- 

 berg regarded it as the rudiment of a visual organ ; and perhaps 

 he is right, for there seems to be very little difference between 

 the pigment of the skin of a Negro and the ])igment of the 

 choroid membrane of his eye, while the latter is eonfined to 

 the eye alone in white-skinned people. Again, in some of the 

 Rotifera, it is not uncommon to see the material of which the 

 red pigment of the eye is composed, more or less dispersed in a 

 molecular form, though it is generally confronted by a bluish 

 refractive matter, corresponding i)crhaps to the vitreous humour 

 and lens. Also, in the so-called blind Plnnaria, there are organs 

 like eyes with flat corneal, but no pigment ; and when the animal 

 is about to divide into two across the stomach, the first indi- 

 cation appears to be an inversion of the integument which is to 

 form the future eye, and at the same time a covering of it with 

 cuticle, which thus supplies the cornea. Finally, then, as we 

 find in the Albino eyes capable of seeing without the j)resence 

 of pigment ; the eye formed by an induj)lication of the skin; the 

 pigment dispersed over the body, as well as in the eye, in the 

 Negro, while it is confined to the eye in the white races, — we are 

 led to the conclusion that the red body in the family oi Euylena, 

 though not necessarily indicating sight, may nevertheless mark 

 the point where something of this nature exists in this, as well 

 as in other Infusoria of the kind, although, as in Astasia, it is 

 not similarly marked, any more than in many animals wherein 

 a visual organ is present without this accompaniment. 



In a small species of Euglena, which dwells in the brackish 

 water of the main-drain of Bombay, and which, after having 

 been placed in fresh water, assumes the still, Protococcus form, 

 multiplying itself by fissiparation and internal segmentation of 

 the sareode, after the manner of vegetable cells, and occasionally 

 in linear arrangement, like the filamentous Alga3, — the red body 

 is as often omitted as re])eated in each cell ; while in the active 

 tstate, previous to longitudinal deduplieation, the red body always 

 becomes dual, one on each side the vesicula. But in transverse 

 fission it is frequently absent in the lower half, and only remains 

 in the longitudinal divisions of the anterior one (fig. 02 a-cl). It 

 is interesting, too, to observe that this body is present in the 

 gonidia of Uluf/iri.v zonata, one of the filamentous Algfc, and that 

 it also is confined to the first cell in fissiparation, which so far 

 corresponds with Euglena, that when the latter assumes a fixed 

 or algoid form, by capsulation, the peduncle of the pellicula is 

 extended from the anterior, ciliated extremity. This also is the 



