Vorficelliiia.] the infusoria. 255 



like, as seen in the engraving. Jig. 235 and 236 (plate v.) ; the 

 lateral crest and frontal wreath, or crown of cilii, are con- 

 tinuous. When kept in glass vessels they often fix them- 

 selves to the sides in clusters. Self-division has not yet 

 been observed. They are best examined under a micro- 

 scope, when placed in a large live-box. A magnifying 

 power of 100 diameters is sufficient. Found amonost 

 vaucheria. Length l-480th. 



387. STEyiTOR polymot'phus. The green Stentor resexn- 

 bles the preceding in form. The ova are of a beautiful 

 green-colour, the gland articulated and chain-like, the 

 lateral crest indistinct, and the frontal wreath of cilii 

 interrupted. This species will not receive indigo readily. 

 Transverse self-divison has been observed. Found upon 

 stones, decayed sticks, and leaves, in standing water. 

 Length 1-1 20th to l-24th. 



388. Stentor igneus. Tlie fire-coloured Stentor is less 

 than the preceding, the ova is of a yellowish-green colour, 

 the skin bright yellow or vermillion, the gland is spherical, 

 lateral plume or crest absent, and the frontal wreath of cilii 

 interrupted. Found by Ehrenberg i;pon the water violet 

 (Hottonia palustris). Length l-72nd. 



389. Stentor niger (Voriicel/a nigra, M.) T/ie 

 brownish- black Stentor is small, of a dark brownish- 

 yellow or blackish colour, the ova olive coloured, the 

 gland is spherical, the lateral crest absent, and the frontal 

 wreath of cilii continuous. This species is often so abun- 

 dant that it colours large pools, in turfy hollows, of a dark 

 black, resembling an infusion of coffee. The swimming 

 movement of this species is readily seen (as in the others) 

 with the naked eye. Size l-96th. 



