138 BIOPLASM OF VALLISNERIA. 



by careful foccussing minute particles of living matter 

 will be brought into view. The movements of the 

 fluid may therefore be compared with the movements 

 of the living bioplasm of an amoeba. In the circu- 

 lating juice of many plants similar appearances may 

 be observed, and in the blood and circulating fluid of 

 all animals, and in man himself, minute particles of 

 living matter are to be demonstrated in immense 

 multitudes. These are diffused through the fluid, 

 and to them is probably due the movement of the 

 contents of the finer vessels and spaces. This con- 

 stituent of the blood, seen with such difficulty that its 

 presence is not yet admitted by observers, is pro- 

 bably the most important, for its increase or diminu- 

 tion may occasion serious disease or death. This 

 almost impalpable living moving matter is the seat of 

 many very important changes, and is perhaps in- 

 fluenced before any other constituents of the body 

 when certain poisons and disease germs find their 

 way into the blood. Protection, after successful 

 vaccination, and the escape from a second attack, 

 which is the rule in the case of many contagious fevers, 

 is most likely brought about by changes induced in 

 the living matter under consideration. 



In health it is upon this material that the coagulable 

 property of the blood is mainly dependent, and it is 

 this which in great part undergoes conversion into 

 what we call fibrin, when the blood is removed from 

 the living vessels or " dies." If destroyed it may, 



