202 OF VITAL MOVEMENTS 



granular in some places than in others. The bioplasm of 

 all organisms, and of the tissues and organs of each 

 organism, exhibits precisely the same characters. It lives, 

 and grows, and forms in the same way, although the con- 

 ditions under which the phenomena of life, growth, and 

 formation are carried on, like the products formed, differ 

 very much in the case of different kinds of bioplasm. A 

 temperature at which one kind will live and grow actively 

 will be fatal to many other kinds. So, too, as regards pabu- 

 lum, substances which are appropriated by one form of 

 bioplasm will act as a poison to another. But the way in 

 which the bioplasm moves, divides and subdivides, grows, 

 and undergoes conversion into tissue, is the same in all. 

 Many remarkable differences in structure, properties, action, 

 and character, are associated with close similarity, if not 

 actual identity of composition. These must, therefore, be 

 attributed not to properties of component elements, to 

 physical forces, chemical affinities, or other characters which 

 we can ascertain or estimate by physical examination, but 

 to a difference in vital power which is inherited, which we 

 cannot isolate, but the existence of which it is unreasonable 

 to deny. 



On Vital Movements. One characteristic of every kind 

 of living matter is spontaneous movement of the matter 

 itself. This, unlike the movement of any kind of non- 

 living matter yet discovered, occurs in all directions, and 

 seems to depend upon changes in the matter itself, and not 

 upon impulses communicated to the particles from without. 

 The movement ought not to be called amceboid, as if it were 

 characteristic of the amoeba, and only exceptionally observed 

 in a few other cases, but it ought to receive a more general 



