ROTIFERA. 



125 



scarcely seem to be consistent with either of the above offices, and 

 therefore we cannot but regard the observations which have been 

 hitherto recorded concerning the nervous system of the rotifera as 

 far from being complete. 



(164.) In addition to the elaborate organization described above, 

 the Prussian naturalist conceived that he had discovered a vascular 

 apparatus, consisting of transverse vessels, (Jig. 51, w, w,) in which 



Fig. 51. 



he supposed a circulation of 

 the nutritive fluids occurred. 

 But the vascular character of 

 the transverse striae visible in 

 this position is more than 

 doubtful, as there seems 

 every reason to suppose that 

 the appearance depicted in 

 the figure is due to the 

 existence of the transverse 

 muscular bands whereby the 

 extrusion of the rotatory ap- 

 paratus is effected, analogous 

 to those occupying a similar 

 situation in the Bryozoa : in 

 fig. 50, i, i, these transverse 

 fasciculi are distinctly de- 

 lineated, and their nature 

 is at once evident. 



(1 65.) The mode in which 

 respiration is effected in the 

 class of animals under consi- 

 deration has been a subject of much dispute. Some have supposed 

 the contact of water, applied to the general surface of the body, 

 sufficient for the aeration of the nutritious juices, especially as its 

 constant renewal would be ensured by the ciliary movements. 

 Bory St. Vincent, * on the contrary, regarded the rotatory cilia 

 as real gills, resembling those of fishes ; and mistaking the move- 

 ments of the gizzard for the contractions of a heart, conceived these 

 animalcules to be even superior to insects in the organization of 

 their vascular system. Ehrenberg, moreover, thinks that he has 

 discovered an internal respiratory apparatus of a most extraordinary 

 description. In Notommata centrura (fig. 50 ) he remarked 

 * Diet, des Sciences Naturelles ; art. Rotifera. 



in. 



