26 THE ACTION OF THE LIVING CELL 



shock could be induced in animals by exposing the 

 viscera to a draught of cold air. Further, the onset 

 of symptoms was found to be accelerated by frequent 

 manipulation of the exposed viscera. After dogs had 

 been caused to pass into a profound state of shock by 

 such means, they were bled and their separated blood- 

 serum was injected into normal dogs. The effects so 

 elicited in the latter were found to be governed by 

 the amount of serum injected. For example, 5 cc. of 

 such serum produced little effect; SO cc. caused the 

 animal to show decided evidence of fatigue; while 

 larger quantities brought about collapse. (Turck, 

 1901.) At that time the analogy was drawn between 

 these results and those obtained by Mosso with fatigue- 

 sttiff. The latter author found that if the blood of a 

 fatigued animal were injected into a normal animal, 

 the unfatigued one showed signs of fatigue. In other 

 words, the production of shock in an animal brings 

 about the presence in the blood of some substance 

 capable of causing the onset of the signs of fatigue in 

 normal animals. As will be shown later, it appears 

 that this substance is cytost, the substance released 

 from injured tissues which, as we have seen, is the 

 primary cause of shock. 



Further, the analogy between the shock-toxin and 

 the fatigue stuff of Mosso is especially interesting for, 

 as will be shown in a later chapter, there exists a close 

 correlation between an animal's resistance to fatigue 

 and to cytost. 



The evidence so far presented refers only to the 

 primary cause of shock, — the release, by injury, of 

 the endocellular substance cytost, which is capable, 

 if present in sufficient concentration, of causing the 



