400 DESCRIPTION OF \Rotatwia. 



power ; a quality discovered by Dr. Goring, and amply 

 explained and illustrated in chapters xvi. and xvii. of the 

 Microscopic Cabinet. Fig. 476 represents a full-grown 

 animalcule extended, with the wheels vibrating, and shews 

 the currents when indigo is put in the water ; it is sup- 

 posed to be attached to a fixed body. Fig. 477 is an under 

 view of the same, with the wheels withdrawn, and the 

 body contracted ; fig. 478 is another, extended, but wheels 

 withdrawn ; this creature, as also figures 479 and 480, 

 which represent the upper portions more highly magnified, 

 have been submitted to different degrees of pressure 

 between the plates of an aquatic crush-box. In figures 

 476 to 478 ova are seen, some are developed, and their 

 eyes and cesophagal bulb visible- The respiratory trans- 

 verse vessels and tube, projecting from the neck, are seen 

 in the engravings. 



The following interesting observations of Dr. Morren are 

 extracted from the Annals of Natural History, vol. vi. : 



" The labours of Keeper show that the cells of Sphag- 

 num are sometimes furnished with openings, which place 

 their interior cavity in communication with the air, or 

 water, in which they are immersed. This skilful observer 

 satisfied himself that, when circumstances are favourable, 

 the Rotifer vulgaris exists in the cells of the Sphagnum ob- 

 tusifolium. This grew in the air, in the middle of a turf pit, 

 but Roeper observed its leaves in water; he does not men- 

 tion whether the infusorial animalcule came from thence, 

 or whether it was previously contained in the cavities of 

 the cells. The general purport of the paper seems to im- 

 ply that these Rotiferi exist in the cells of that part of the 

 plant which was exposed to the air, and, in this case, the 



