INFUSORIA 439 



and as it goes it rolls irregularly over and over in all 

 directions, not revolving on its long axis, and thus giving 

 you very satisfactory views though only momentary of 

 the keel with which the back is furnished. It is in the 

 turnings of such minute creatures that the microscopist 

 often gets a glimpse of peculiarities of form which a view 

 of the animal when in repose, however long continued, 

 fails to reveal. Longitudinal interrupted lines are seen 

 running down the body of this pretty leaf, which do not 

 appear to mark irregularities of the surface, and there- 

 fore are probably internal. Ehrenberg calls these and 

 similar collections of granules "ova," or eggs; but this 

 is to cut the knot, instead of untying it. There is 

 no sufficient reason to believe that these animals increase 

 by ova. 



About the front of all these EuglencB, you may discern 

 now and then a slight flickering or quivering in the water. 

 The power we are using, though best for the general dis- 

 play of the form, is insufficient to resolve this appearance: 

 I will put on a higher objective. You now see that there 

 proceeds from the frontal part of the body a long and 

 very slender filament, which is whisked about in the man- 

 ner of a whiplash. This is considered to be the organ of 

 locomotion; but I rather doubt that such is the function; 

 the smooth and even gliding, often rotating, of the creat- 

 ure, seems more like that produced by minute and gener- 

 ally distributed cilise than that caused by the lashings of 

 a single long thread. 



Yet two more species of this extensive genus we dis- 

 cern in this well-stocked drop of water. They have re- 

 ceived the appellations of the Pear (E. pyrum), and the 

 Sloth (E. deses). The former is the most minute we have 



