73 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 1 



Breinl and Kinghorn-^ to be new to science and described as Spirillum 

 duttoni. This spirochaetae can be transmitted from animal to animal 

 by the bite of the Tampan Tick, Ornithodoros savignyi var. caecus 

 (^mouhata) . In the experiments of Button and Todd, rabbits, guinea 

 pigs, rats and monkeys were used. The infection was found to pass 

 through the egg. Koch*^ working independently in German East 

 Africa in 1904 made the same discovery. He found the spirochaetae 

 to multiply within the egg and that the young ticks from infected 

 localities are capable of infecting monkeys. 



Skinner-- states it his belief that the ticks common on rats in India 

 transmit the plague bacillus. 



The connection between ticks and Rocky Mountain spotted fever 

 of man in this country has been the subject of considerable investiga- 

 tion. Dr. H. T. Ricketts^s of Chicago and Dr. W. W. King-* of the 

 United States Public Health and Marine Hospital Service have suc- 

 ceeded in transmitting the disease from one guinea pig to another by 

 the application of Dermacentor occidentalis. Later, Doctor Rieketts 

 has produced the disease in a guinea pig through the attachment of 

 36 males which were collected partly from horses and cows and partly 

 from the vegetation in the vicinity where the disease occurs. This 

 seems to prove that the tick is the natural transmitter of the disease. 



For some time it was thought that louping ill, a disease of sheep 

 in Scotland, was transmitted by the European Castor Bean Tick, 

 Ixodes ricinus, but Wheler^^ recently states that this apparently has 

 been disproven. 



Modder-^ states his belief that the yaws of paranghi disease of man 

 and cattle in Ceylon, which is produced by a spirochaete, is trans- 

 mitted by a tick. Bettencourt, Franca and Borges-^ have described 

 from a deer in a park at Mafra, Portugal, a bacilliform plasma which 

 they believe to be introduced into Europe by ticks from zebus in 

 the park. 



Laveran and Negre^® suggest the possible transmission of a disease 

 in an African land turtle, due to a Haemagregarine, by the Bont Leg 

 Tick (Hyalomma aegyptium.) 



In this country Professor H. A. Morgan^® has studied several species 

 and has determined that neither Dermacentor variabilis nor Amhly- 

 omma amrericanum transmit splenetic or Texas fever. Dr. N. S. 

 Mayo^'* has reached the same conclusion with the latter species. 



Aside from splenetic or Texas fever and Rocky Mountain spotted 

 fever, no disease in this country has been determined as transmitted 

 by ticks, although it is suspected that spirillosis of fowls may occur 

 and be thus transmitted in southwestern Texas. It has also been 

 pointed out to the writer by Prof. H. A. Morgan that hunting dogs 



