24G ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



only sparsely to be seen. The inference is irresistible that 

 in regard to the very minute Bacteria germs, though we do 

 not yet know how they are produced, nor can we detect them 

 with the microscope, yet they do exist, and remain floating 

 long after all others are deposited. 



M. Pasteur asserts that Bacteria present themselves under 

 two forms first as rods, which alcohol, compressed oxygen, 

 desiccation, and a temperature lower than 100 C. can de- 

 stroy; and, secondly, as highly refracting corpuscles, which, 

 on the other hand, resist a temperature of 120 C, and resist 

 also the action of alcohol and of compressed oxygen. These 

 he regards as a mode of generation of the Bacteria. They 

 do, of course, also multiply by segmentation ; but often, on 

 one or several points of the Bacterium, globular, highly re- 

 fracting corpuscles arise, the diameter of which is not great- 

 er than the thickness of the Bacterium. After these appear, 

 the rest of the rod quickly disappears. If an appropriate 

 liquid is inoculated with these corpuscles, Bacteria are de- 

 veloped in it, just as if the liquid w T ere inoculated with rod- 

 like Bacteria, and they constitute the resisting power of the 

 liquids experimented on by some authors. 



MONADS AND AMCEB^E. 



Herr Cienkowsky.well known for his researches on monads, 

 has recently contributed some additional information upon 

 these and allied organisms, which appear to show that the 

 boundary -lines which it has so long been usual to draw 

 between plant and animal organisms, and between the indi- 

 vidual groups of those lowest forms of life, appear more and 

 more illusory, and the supposition is recommended of a com- 

 mon lowest kingdom of organisms, that of Protista (Haeckel), 

 out of which animals and plants have by degrees been differ- 

 entiated. 



At the meeting of the Philadelphia Academy in October 

 last, Dr. Leidy gave an interesting account of a cannibal 

 Amoeba (A. Umax ?), which, after a period of seven hours, 

 succeeded in digesting, or at least absorbing until it disap- 

 peared among the granular matter of its entosarc, another 

 ^\iiioeba (A. verrucosa), thus appropriating its structure to its 

 own, just as we might do a piece of flesh completely, with- 

 out there being any excrementitious matter to be voided. 



