INFUSORIA. 



IOI 



vacillating manner. The globule is formed of a homogeneous trans- 

 parent substance, which throws out obliquely a whip-like filament, 

 three, four, or even five times the length of the body of 

 the Monad. 



The genus Cercomonas of Dujardin has its body pyri- 

 form, having in front a vibratile filament, very long, very 

 flexible, and easily agitated. Behind the body there is a 

 thicker straight filament attaching itself sometimes to 

 neighbouring corpuscles, round which, in this case, the 

 Cercomonad oscillates like the ball of a pendulum round 

 its stem. 



The Euglencea are infusoria usually of a green or red 

 colour. Their form is very variable. They are oblong 

 or fusiform in shape, swelling at the middle during loco- 

 motion, and contracted or bowl-shaped in repose, or after death. 

 They are furnished with the usual whip-shaped filament, which issues 

 from an opening in front, and pos- 

 sess one or many reddish points 

 irregularly placed anteriorly. 



Euglena viridis (Fig. 35 ) is the 

 most common species, and among 

 the most widely diffused of all the 

 Infusoria. It is this animalcule 

 which is often met covering stag- 

 nant pools with a floating surface 

 of green, and which forms on the 

 surface of marshy waters the shin- 

 ing pellicle so strongly coloured, 

 which, collected upon paper, so 

 long preserves its brilliant tint. 



The Euglena sanguined, at first 

 green, becomes subsequently of 

 a blood colour. It has often 

 been met with by microscopists. 

 Ehrenberg, who first described 

 it, attributes to its great abun- 

 dance the red colour of some 

 stagnant waters. Its presence 

 may perhaps explain the pre- 

 tended miracle of water changing 

 into blood, which was frequently 

 invoked by the Egyptian priests. Eug i ena virid is (Ehl g ), Magnified 3S o times. 



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