BACTERIAL INVASION 221 



when any highly invasive microorganism gains ac- 

 cess to the body v^e may expect an analogous behavior 

 — that is, a cytost effect in some respects comparable 

 to that obtained in the experiments cited. Obviously 

 the severity of such an effect vsrill depend upon both 

 the cytost available for adsorption upon the bacteria 

 and the invasiveness of the infecting organism. 

 Further, if, as we have shown, the latter is capable 

 of causing the disintegration of tissue and thence lib- 

 erating cytost, the host is forced to cope with a three- 

 fold difficulty. 



In previous chapters it has been shown that vari- 

 ous chronic disturbances, especially of the organs of 

 endodermal origin, may be brought about by the con- 

 tinued injection of sublethal quantities of homolo- 

 gous cytost. From this, it may be deduced that, by 

 the combined action of bacteria and small quantities 

 of homologous cytost for a protracted period of time, 

 similar chronic conditions may be induced. This is a 

 concept rather difficult to subject to experimental test, 

 since animals vary so in the rapidity of their response 

 to sublethal quantities of cytost. Nevertheless the 

 conclusion seems logical. 



It is relatively easy to understand the importance 

 of all these considerations in the case of animals actu- 

 ally suffering from an acute infection, although at 

 first sight they do not appear to be of special impor- 

 tance in the life of an animal not suffering from infec- 

 tious disease. There are, however, a number of dis- 

 eases known to science which have all the earmarks 

 of being infectious, but for which up to the present 

 time no specific causative factor has been found. In 

 some instances such ailments may be traced to a non- 



