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



also, there are the same reasons against the supposition of an 

 intestinal tube, as in that of the lines appearing before and 

 behind a fusiform mass : here likewise, not only the form, but 

 also the length of the curve varies : whilst at one time it is but 

 short, and soon terminates by the intermixture of the particles 

 contained in it with the surrounding mass, it may immediately 

 afterwards be twice as long or longvr*, a variation which appears 

 only to depend upon the force with which the cilia of the rotatory 

 organ act ; so that we cannot explain the whole phsenomenon 

 otherwise than that the water with the particles contained in it 

 streaming with some rapidity into the mass with which the body 

 is filled, cannot mix with the latter immediately, but only when 

 its rapidity of motion is diminished by friction; just as we see 

 a rapid stream which falls into a sluggish or stagnant pool, or 

 into the sea, still retaining its independence for a certain space, 

 so that if it differs iu its colour or turbidity from the water of 

 the sea or pool, we may distinguish it from the latter, with which 

 it does not mix for a long time, in the form of a streak, which is 

 often of great length. 



When the nutritive particles in the body of the VoriiceUa 

 have attained the end of the clear streak under a constant dani- 

 nution of their rapidity, and in the other case, when the morsel 

 has lost its spindle-shape and become globular, they have no 

 longer any separate movement, but now only take part in a cir- 

 culatory motion, in which all the parts in the interior of the body, 

 with the exception of the band-like organ (testicle, according to 

 Ehrenberg; nucleus of Von Siebold and most recent authorsf), 

 are engaged. This circulation is usually slow (slower than in 

 the grean Pca-amecium Bwsaria,¥ocke), and therefore generally 

 overlooked ; it rarely ceases for a time entirely. The morsel of 

 food performs sometimes more, sometimes fewer circuits with the 

 rotating mass, until at last it arrives in the vicinity of the anus 

 (e), when its circulation ceases, and the anus opens and allows 

 the mass to escape into the vestibulum (fig. 3 e). 



From this description of the processes of nutrition in the 

 VorticellincB, it may be seen at once that it is impossible to attri- 

 bute to them an intestine with many adherent vesicular stomachs, 

 as Ehrenberg supposes. The existence of the circulation of the 

 entire contents of the body contradicts this supposition. Ehren- 

 berg himself soon saw the insufficiency of the first explanation 



* It may even make a complete circuit and return nearly to its point of 

 commencement beneath the pharynx. 



t As we shall hereafter see that the signification of this organ cannot 

 3'et be established with certainty, we shall provisionally retain the name of 

 nucleus, but without wishing to attach thereto the idea of a cell-nucleus. 



