MAR 7 1902 



DENDlfOCOlMETES PARADOXUS. 325 



Dendrocometes paradoxus. 



Part I — Conjugation. 



By 



Sydney J. Ilirkson, M.A., D.Sc, F.R.S., 



Beyer Professor of Zoology in the Owens College, Manciiester 



Assisted by 

 mr. J. T. Wadswoitli. 



With Plates 17 and 18. 



Introduction. 



There is no species of the class Acinetaria that can be 

 obtained with greater facility at all times of the year than 

 Dendrocometes paradoxus (Steiu). This is due to the 

 fact that it is found with unfailing regularity on the gills of 

 our commonest fresh-water Crustacean, Gammarus pulex. 



In addition to the fact that it is readily obtained, however, 

 it presents us with the further advantage of being attached 

 to a soft and tolerably transparent gill, which can be easily 

 seen with the naked eye, and manipulated without difficulty 

 on the slide and in the paraffin bath. The difficulties that 

 have usually to be overcome in preserving and staining the 

 Infusoria whole or in sections are, in this form, largely 

 obviated, and it is not very difficult, after the preliminary exa- 

 mination of the specimens attached to any one gill, to imbed 

 and cut them into a series of sections in any plane that may 

 be desired. Possessing these advantages, it was obvious 

 that a careful examination of the changes of the nuclei 



VOL. 45, PART 3, NEW SERIES. Z 



