Vihrionia.l infusoeial ANiMALcrLES. 1(J9 



larger forms, and of a more fine and solid structure, represent the 

 more advanced fonns, and us all Algae, as they advance in size, tend 

 to consolidate into mycodermous forms, losing much of their primi- 

 tive cell-structure, so these two genera appear to have lost their old 

 beaded type. As for the two remaining genera, Spirochoeta and 

 Spirodiscus, but little is positively known. They scarcely appear to 

 belong to the other forms of this family, and as Ehrenberg liimself 

 has expressed a doubt upon the subject, one may as well omit a 

 further notice. Therefore, in a structural point of view, the species 

 of this family seem to be only Algoe at diifei-ent stages of growth." 



Genus BACXEEnrM. The j'omted-wand Animalctdes are distinguished 

 by being connected together in a thread-like chain, of an inflexible 

 nature, and by propagating by transverse self-division. 



The three species known to us are colourless, and extremely 

 minute. Ehrenberg remarks, " that only one of the species has been 

 satisfactorily determined, and that their organic relations are alto- 

 gether so occult, that our judgment respecting them must unavoidably 

 be left in a fluctuating state." In B. triloculare, organization is dis- 

 coverable to the extent of a vibratory proboscis, a granulated mass 

 within the body of the creature, and a faculty of spontaneous 

 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 displaying the individuals or links of 

 ■which the wand-like cluster is composed. I have generally met with 

 Bacterium around decomposed vegetable matter, on the surface of 

 water containing chara, &c. 



B. triloculare. Chain consists of from two to five animalcules, of 

 an oval form, developed in short cylinders, generally about thi'ce 

 times as long as their diameter, and marked with transverse lines. 

 Ehrenberg has observed not more than five links together nor less 

 than two, a single animalcule never having faUen 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 

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

 though short proboscis, is seen, which, in the larger specimens, is 

 one-third the length of the bodj', and in the smaller, one half. The 



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