Dr. C. F. J. Lachmann on the Organization of Infusoria. 121 



name of pharynx, which is open to but little objection. This 

 pharynx is not merely a vacuity in the surrounding jjelatinous 

 substance, only produced by the water whirled into it, but it has 

 proper walls which preserve its fusiform shape, even when no 

 food is contained in it. 



The morsel passed from the pharynx into the interior of the 

 body runs nearly to the posterior extremity of the Vorticella, 

 and then turning upwards (hg. 4 /) rises on the side of the body 

 opposite to the pharynx. During this portion of its course, it 

 usually still retains the spindle-shape communicated to it by the 

 pharynx, and only here changes to the globular form, often rather 

 suddenly : this induced me at first to think that the morsel was 

 still enclosed in a tube during this part of its course, and this 

 opinion seemed to be supported by the circumstance that before 

 and behind the morsel, two lines are not unfrequently seen 

 (fig. 4 /), which unite at a short distance from it, like the outlines 

 of a tube which it has dilated. Subsequent observations, how- 

 ever, have again shown me that this opinion is an improbable 

 one, for the circumstances described must also occur, when a 

 fusiform morsel is passed with some force and rapidity through 

 a quiescent or slow-moving tenacious fluid mass : the above- 

 mentioned lines, before and behind the morsel, must be produced 

 by the separation and reunion of the gelatinous mass, even if 

 the morsel is not surrounded by a tube. But the existence 

 of a tube depending from the pharynx appears also to be directly 

 contradicted by the fact, that on the one hand the curves de- 

 scribed by the morsel are sometimes larger and sometimes 

 smaller, and on the other that the morsel acquires the globular 

 form sometimes sooner and sometimes later, according as it is 

 pushed out of the pharynx with greater or less force and rapidity. 

 The masses whirled into the pharynx are not always aggregated 

 into a morsel, but sometimes, under conditions which have not 

 yet been satisfactorily ascertained, all the masses which reach 

 the pharynx are seen to pass quickly through it without staying 

 in it j they then stream through the mass surrounding them in 

 a clear streak, which, like the morsels, describes a curve at the 

 bottom of the bell, and only mix with the mass when their ra- 

 pidity of motion has diminished*. We might easily be inclined 

 to regard the clear, bent streak with the particles flowing in it, 

 as an intestine; and this has probably been done by Ehrenberg, 

 who states that he distinctly saw the bent intestine in some Vorti- 

 cellina, especially in Epistylis plicatilis, in which I have also been 

 able to study the phsenomenon very closely. But in this case, 



* A roundish morsel, which might be regarded as a full stomach, is then 

 never formed. 



