AMONG SrXII'LESAECaDE ORGANISMS. : .269- 



creeping by means of the appendages situated along tlie sides of 

 its body. 



Fig. 3. .. . :, 



Mastigamceba aspera, as seen when ci*eeping ovev the field of the microscope. 

 (After F. E. Schulze.) 



In the body may be distinguished a strongly refringent, hyaline, 

 colourless eetosarc, from which the pseudopodia directly proceed, 

 and a softer endosarc loaded with clear reddish yellow spherules 

 and colourless granules, and usually containing also the masses of 

 ingested nutriment. The greater part of the external surface is 

 beset with very minute, refringent, rod-like structures, compared 

 by the author to certain Bacteria (^Bacteria termo) . These usually 

 lie tangentially to the surface, to which they give a peculiar rough- 

 ness, which has suggested the specific name. During the act of 

 creeping the posterior pseudopodia are usually reduced to the 

 condition of short thick processes, from which may be seen 

 radiating extremely fine sarcode projections, quite like the fine 

 processes observed on the hinder end of certaiu Amoeh(s (Amoeba 

 vrinceps), where they give a kind of flocculent appearance to the 

 surface. The endosarc at the boundary between it and the eeto- 

 sarc contains one or two vacuoles, which always lie at the hinder 

 end and alternately appear and disappear, without, however, show- 

 ing any distinctly rhythmical pulsation. 



