132 DESCRIPTION OF [Polygastrica. 



extremely minute. Ehrenberg remarks, " that only one of 

 the species has been satisfactorily determined, and that 

 their organic relations are altogether so occult, that our 

 judgment respecting them must unavoidably be left in a fluc- 

 tuating state." InB. triloculare, organization is discoverable 

 to the extent of a vibratory proboscis, a granulated mass 

 within the body of the creature, and its faculty of spon- 

 taneous division. The only animal endowment common 

 to all the species is an active and voluntary power of 

 locomotion. 



A magnifying power below 500 times linear will not 

 exhibit the divisions or transverse lines where the indi- 

 viduals or links of which the wand-like cluster is composed 

 are united. I have generally met with them around decom- 

 posed vegetable matter, on the surface of water containing 

 char a, &c. 



89. BACTERIUM triloculare. The three-celled Bacterium. 

 Chain consists of from two to five animalcules, of an oval 

 form, developed in short cylinders, generally about three 

 times as long as their diameter, and marked with trans- 

 verse lines. Ehrenberg has observed not more than five 

 links together nor less than two, a single animalcule never 

 having fallen under his notice. By throwing a little 

 colouring matter into the water, an evident vibration may 

 be perceived in it near the anterior portion of the animal- 

 cule ; and upon a very close inspection, a simple filiform, 

 though short proboscis, is seen, which, in the larger speci- 

 mens, is one-third the length of the body, and in the 

 smaller, one half. The motion of this creature is tremu- 

 lous, or slowly revolving upon its longitudinal axis. 

 Found in the water of bogs. Length of cluster, 1 -4800th 



