Ticks and Mites 



33 



*t. That the period of activity of the disease is lim- 

 ited to the season during which the adult female and 

 male ticks attack man. 



"2. That in practically all cases of this disease it 

 can be shown that the patient has been bitten by a 

 tick. 



"3. That the period between the tick bite and the 

 onset of the disease in the many animals he has ex- 

 perimented with corresponds very closely to this period 

 as observed in man. 



"4. That infected ticks are to be found in the lo- 

 cality where the disease occurs. 



"5. That the virus of spotted fever is very inti- 

 mately associated with the tissues of the tick's body as 

 is shown by the fact that the female passes the infection 

 on to her young through her eggs, and further, by the 

 observation that in either of the two earlier stages of 

 the life cycle the disease may be contracted by biting 

 a sick animal and communicated to other animals 

 after molting or even after passing through an inter- 

 mediate stage." 



Professor R. A. Cooley of Montana, from whose 

 report the above quotation is taken, has also made 

 studies of the habits of the tick and believes there 

 can be no doubt that it is the disseminator of the 

 disease. 



Relapsing Fever. The relapsing fever is an in- 

 fectious disease or possibly a group of closely re- 



