104 THE NATURALlSl'. 



NOTES ON THE ROTIFERA. 



By J. Cash, Warrington. 



Among the many sources of enjoyment which the student of Natural 

 History has at his command, there are few equal to — certainly none sur- 

 passing — that of searching out and forming an acquaintance with the 

 hahits, &c., of the denizens of our pools and ditches. The expense of 

 microscopes, which formerly was a great obstacle to the popularity of this 

 pursuit, is now happily, in a great measure, removed. Instruments are 

 sold at a moderate price which are sufficient for a very large proportion of 

 microscopical investigations. In the case of the Eotifera, a power of from 

 one to three hundred diameters is ample. If, however, the student is 

 desirous of studying the peculiarities of structure — especially of the more 

 minute species — he will require a considerably higher power ; but it is 

 astonishing what an amount of work can be done with an instrument 

 costing not more than three or five guineas. 



In gathering Rotifera the student should provide himself with half-a- 

 dozen, or more, small wide-mouthed glass bottles, and should search out 

 those ponds where there is a good supply of the finer leaved water plants, 

 such as Ranunculus aquatilis, MyriopliyUum verticillatum, Hottonia palustris, 

 &c. ; although plants of more robust growth are not to be entirely over- 

 looked. I have found some of the rarest species on the leaf-stems of 

 Hydrocharis. When they occur in this situation, however, they cannot 

 be examined under the microscope. Many good things are to be found 

 u]^on Anachar is ; I have seen scores of Melicerta cases upon a single stem. 

 A small portion of the plant should be removed carefully from its place of 

 growth and transferred to a bottle previously filled with water. By the 

 aid of a pocket lens the value of the collection may be easily ascertained — 

 indeed this may be often settled with the naked eye, for some of the larger 

 Rotifera are distinctly visible without any microscopic aid whatever. Only 

 a few days ago there appeared an uncommonly fine Stephanoceros in my 

 aquarium, which, placed in a favourable position with regard to the light, 

 I could distinctly see at a distance of nearly two yards. 



It may not be out of place here to observe that the aquarium is a 

 most valuable — indeed an indispensable — adjunct to the microscope, and 

 the student of infusoria should not be without one on any account. A 



