THE BEGINNINGS OF LIFE. 



275 



bending of the body, or else an actual progression of 

 an undulating anguilluloid character. In size they may 

 vary from that of the largest Bacterium up to a body 

 siV' in length by T7 VrjV' in breadth, though there is no 

 definite limit to their dimensions. Notwithstanding 

 the observations of Dumas and Bennett, it cannot be 

 considered that these are ordinarily produced by the 

 aggregation of Bacteria. It seems much more consistent 

 with what may be observed, to believe that they arise 

 by the gradual development of simple Bacteria, which 

 from some cause unknown to us do not undergo 

 such frequent processes of fission, and possess a great 

 inherent power of growth. M. Davaine has also 

 described certain straight or slightly bent, though 

 motionless, bodies, closely resembling Vibriones as far as 

 size and general appearance are concerned, to which 

 he has given the name Bacteridia*. These are the 

 organisms met with in the blood of animals suffering 



1 He looks upon Bacteria and Vibrio as genera which are closely 

 allied to the Oscillator ice, and thinks that these Bacteridia form a still 

 closer connecting link. Many of them are, in fact, even longer than 

 Vibriones, and therefore in point of size they do approach more closely 

 to the Oscillatoria. M. Davaine says he has also met with many kinds of 

 Vibriones in the intestines of mammals and birds, as well as in salt-water 

 infusions, which have been invariably motionless throughout their whole 

 period of existence. He maintains that when those species which have 

 previously exhibited movements cease to manifest them, we must by no 

 means look upon them as necessarily dead : such organisms may pre- 

 serve an unchanged appearance for many days or weeks, whilst, when 

 they really die, they undergo disintegration in from twelve to twenty- 

 four hours. (See ' Compt. Rend." 1864, and 4 Gaz. Med. de Paris,' 

 1864.) 



T 2 



