GENUS AMOEBA— AMCEBA PBOTEUS. 35 



perpetuate the name given to the animal by its discoverer. I therefore 

 suggest that the name of Amoeba proteus should be employed for the 

 common large Amoeba, recognizable as the Proteus of Rosel and the 

 Amoeba princeps of Ehrenberg ; otherwise, according to the strict rules of 

 scientific nomenclature, it should be Amoeba chaos. 



Auacpfoa proteus (pis. I, II) is one of the largest forms of the genus, 

 and is the one which is perhaps the most familiar to those who are accustomed 

 to the examination of the microscopic life abounding in fresh waters. It is 

 commonly found in the superficial ooze of clear and comparatively quiet 

 waters, such as ponds, lakes, and ditches. It also occurs among- Duck-meat 

 and on the under surface of leaves of aquatic plants floating on the surface of 

 water. In some instances, in certain localities, ithiav be found in profusion; 

 but frequently in similar places, or even at other seasons in the same 

 place, I have failed to obtain it after the most diligent search. Specimens 

 often vary, especially in different localities, to such a degree that it is 

 difficult to decide whether to regard them as really pertaining to this or 

 some other described species. 



The habitual appearance of characteristic forms as they have come 

 within my notice may be described as follows : 



The Amoeba, if observed immediately after having been transferred 

 from the material in which it lived to the object-glass of the microscope, 

 appears as a globular or ovoidal, granular ball, translucent and of a blackish 

 hue by transmitted light, or faintly yellowish white by reflected light. 

 Often, however, from the first moment of observation, the animal appears of 

 irregular shape, with projected pseudopods already in movement, apparently 

 as if it had been little affected by disturbance. 



The globular or ovoidal quiescent Amoeba after a little while puts 

 forth from every part of the body a multitude of clear, rounded extensions 

 of the ectosarc, which give one the impression that the creature had sud- 

 denly exuded, or, if I may use the term, sweated, numerous drops of liquid. 

 These quickly elongate, and assume the form of digitate pseudopods, in 

 which condition the animal may present the appearance seen in fig. 1, pi. 

 I. A number of the pseudopods continue to elongate and become thicker, 

 not only from an extension of the ectosarc, but by the attendant influx of 

 the endosarc. The greater number of the pseudopods originally seen are 



