LOCATION OF INFECTIVE ORGANISMS 227 



SPECIFICITY OF LOCATION OF INFECTIVE ORGANISMS. 



It is readily apparent that certain disease organisms tend 

 to locate themselves in definite regions and the question 

 arises, Is this diie to any specific relationship between organ- 

 ism and tissue or not? Diphtheria in man usually attacks 

 the tonsils first, gonorrhea and syphilis the external geni- 

 tals, tuberculosis the lung apex (in man most commonly), 

 "choleras" the small intestine, "dysenteries" the large 

 intestine, influenza the limgs. In these cases the explana- 

 tion is probably that the points attacked are the places 

 where the organism is most commonly carried, with no 

 specific relationship, since all of these organisms (Asiatic 

 cholera, excepted) also produce lesions in other parts of the 

 body when they reach them. On the other hand, the virus of 

 hydrophobia attacks nerve cells, leprosy frequently singles 

 out nerves, glanders bacilli introduced into the abdominal 

 cavity of a young male guinea-pig cause an inflammation 

 of the testicle, malarial parasites and piroplasms attack the 

 red blood corpuscles, etc. In these cases there is apparently 

 a real chemical relationship, as there is also between the 

 toxins of bacteria and certain tissue cells (tetanus toxin and 

 nerve cells). Whether "chemotherapy" will ever profit 

 from a knowledge of such chemical relationships remains 

 to be developed. 



