318 Dr. A. G ruber on Protozoa. 



itself measures about 0*15 millim., or at least its larger forms, 

 and lias the same structure as the other Stichotrichce re- 

 ferred to. 



While hitherto only such representatives of the genus 



Stichotriclia have been known as secrete domiciles con- 

 sisting of a gelatinous material covered with granules of all 

 kinds, one species, which I shall name Stickotricha urnula 7 

 behaves quite differently. It lives in a transparent membra- 

 nous capsule of a flask-like shape, closed throughout except 

 a narrow anterior opening (fig. 7), and scarcely ever quits 

 it. The edges surrounding the aperture have a tendency 

 to fall together when the Infusorian is entirely retracted 

 within the carapace. The envelopes of Stichotricha differ 

 from those of many peritrichous Infusoria {e.g. the Cothurnice) 

 in that they are not attached to any support ; hence the bottom 

 of the flask is completely rounded off. They have a greater 

 resemblance to those capsules which many Heterotricha (such 

 as the species of Freia) construct for themselves. The length 

 ot the capsule is about 0*07 millim. in the full-grown forms. 

 The animal which dwells in this envelope differs notably 

 from the previously mentioned species of Sticltotricha, but, it 

 seems to me, not sufficiently to necessitate the creation of a 

 new genus for it. 



The difference becomes especially perceptible when the 

 Infusorian stretches the anterior or neck part far out of the 

 carapace, in order to procure food by the action of its cilia 

 (fig. 7). In this state the hinder part of the body is not 

 pointed, as elsewhere in this genus, but rounded off in the 

 form of a ball or club ; u e. it assumes exactly the form of the 

 bottom of the flask, from which it is separated by a small 

 interval. This thick part of the body then narrows suddenly 

 to form the neck, which is protruded far out of the carapace, 

 and bends towards one side, as is proper to all Stichotricha\ 

 It may also happen that nearly the whole animal is drawn out 

 in length, by which means the neck acquires a still further 

 extension. This shows how extraordinarily contractile the 

 body-substance of Stichotricha urnula is. When the Infu- 

 sorian retracts itself into the capsule it loses this peculiar form, 

 and then exhibits the ordinary structure of an Oxytrichine. 



The protoplasm of the body is very rich in granules and 

 consequently opaque, so that 1 have never succeeded in de- 

 tecting any thing of the nucleus in the living animal. By 

 staining with carmine solution, however, it immediately ap- 

 pears distinctly. It consists of two bean-shaped bodies, such 

 as are typical of the family. Very frequently both of them 

 are not placed perpendicular to the longitudinal axis of the 





