VITALITY AND DECOMPOSITION. 95 



at, for we can do so without drawing upon our imagination in 

 the least. I have already pointed out the exceedingly simple 

 structure of the Rhizopods, particularly that of Amoeba (page 

 9). The closest examination of this animal does not reveal the 

 least sign of a cell-like structure ; it is merely a mucous or gum- 

 like moving mass, which could not possibly be more simple 

 unless it were resolved into a fluid condition. This creature 

 may be divided, and even divides itself, more minutely than the 

 Hydra allows ; in fact, there is no conceivable limit to the 

 minuteness with which it may be cut up, any more than you 

 could imagine a limit to the minuteness with which a drop of 

 water may be divided ; and yet each subdivision moves and 

 seizes its prey just as does the main stock from which it was 

 separated. We could not imagine a more minute subdivision 

 unless it were reduced to the ultimate atoms of the physicist, or 

 actually decomposed ; nor could one possibly expect it to come 

 nearer to absolute decaying decomposition and yet retain the 

 appearance of life. 



This brings me now to the relation of some experiments, 

 upon decomposing tissues, to ascertain what are the limits of 

 the manifestations of life in animals. It is now five years since 

 I first noticed the curious phenomena which I am about to 

 describe. The experiment, or rather the discovery, was made 

 known immediately after the investigation, and as it was writ- 

 ten for publication whilst the subject was fresh in my mind, I 

 will extract a part of the original article as it appeared in the 

 proceedings of the American Academy. 



" A discovery, which I made on the 20th of March, (1859,) may 

 not be uninteresting, as it has more or less relations in its nature 

 to the theory so earnestly advocated by Pouchet. There are 

 certain well-known bodies described as animals by Ehrenberg, 

 under the name of Vibrio ; their peculiarity consists in that they 

 are composed of a single row of globular bodies, resembling a 

 string of beads, more or less curved, and move in a spiral path 

 with great velocity, even faster than the eye can follow in many 

 cases. They have always been spoken of as developing around 



