CHAPTER II 



SPH^RELLA AND EUGLENA MONADS AND BACTERIA 

 DIFFERENCES BETWEEN ANIMALS AND PLANTS SAPRO- 

 PHYTES. 



THE rain-water which collects in puddles, open gutters, 

 &c., is frequently found to have a green or red colour. The 

 colour is due to the presence of various organisms 

 plants or animals one of the commonest of which is 

 Sphczrella (or, as it is sometimes called, Hczmatococcus or 

 Protococcus) pluvialis. 



Like Amoeba, Sphaerella is so small as to require a 

 high power for its examination. Magnified three or four 

 hundred diameters it has the appearance (Fig. 68, A) 

 of an ovoidal body, somewhat pointed at one end, and 

 of a bright green colour, more or less flecked with bright 

 red. 



Like Amoeba, moreover, it is in constant movement, 

 but the character of the movement is very different in 

 the two cases. An active Sphaerella is seen to swim about 

 the field of the microscope in all directions and with 

 considerable apparent rapidity. We say apparent rapidity 

 because the rate of progression is magnified to the same 

 extent as the organism itself, and what appears a racing 

 speed under the microscope is actually a very slow crawl 



