448 EVENINGS AT THE MIOEOSCOPE. 



discern in this well-stocked drop of water. They have 

 received the appellations of the Pear {K pyrum), and 

 the Sloth {E. deses). The former is the most minute 

 we have yet seen, and seems to be scarce ; but it is 

 highly curious and interesting in appearance. It much 

 resembles, in outline, a fish of the genus Batistes / the 

 muzzle being somewhat protruded and truncate, and the 

 form rhomboidal; it terminates in a slender pointed 

 tail. The body is obliquely fluted, which gives a very 

 singular effect; for from the transparency of the tissues 

 the lines of the opposite side can be discerned crossing 

 those next the eye, and dividing the animal into lozenge- 

 shaped areas. The colour is sparkling green, but the 

 tail and the edges of the body are clear and colourless : 

 and there is a bright red eye. At other times this 

 Euglena takes the form of a claret-bottle, or an oil-flask ; 

 the muzzle being bi'oadly truncate, or even indented.. 



Its motion is rapid ; a swift gliding in the direction 

 of its long axis ; it turns continually on the same axis, 

 which gives a waving irregularity to its course ; and 

 has a pretty effect from the continual crossing of the 

 flutings in the revolving. This specimen is abont T^oth 

 of an inch in length, including the tail. 



Euglena deses is much larger, being about aJoth of 

 an inch in length, though the tail is very short. It has a 

 thick body; with around blunt head; it tapers suddenly 

 to the tail. Its colour is bright green with a red eye ; 

 but the presence of an infinite number of irregular 

 oblong granules and lines, with several globular vesi- 

 cles, gives an opacity and a blackness to its appearance. 

 In its manners it is sluggish ; it never swims or glides 

 gracefully and swiftly among its playful congeners, but 

 contents itself with twining slowly among the flo.cose 



