DISEASES CAUSED OR CARRIED BY MITES AND TICKS 419 



organs, very seldom in tlie salivary glands, and not at all in the coxal 

 fluid. Leishman in 1910 proved that the organism is voided in Mal- 

 pighian excrement while the tick is feeding, and, by means of an anti- 

 coagulin coxal fluid voided at the same time, is washed into the wound. 

 Infection does not take place through the proboscis. Leishman's experi- 

 ments were completely checked and substantiated by Hindle (1911), who 

 demonstrated that the infection was due to the presence of the spiro- 

 chaetes in the white Malpighian secretions, and entered the feeding punc- 

 tures with uninfected coxal fluid ; and, furthermore, dissections prove 

 that the salivary glands of these particular ticks were not infected, while 

 the gut contents, sexual organs and jNIalpighian tubules were. Inocula- 

 tion of these various organs gave incubation of spirochaetes in 7 to 9 

 days. 



Spiroschaudinnia granulosa (Balfour), cause of Sudanese or North 

 African FOWL SPIROCHAETOSIS, was proven by Balfour to be 

 transmissible by Argas persicus (Oken) Fischer Von Waldheim. 



Spiroschaudinnia marchouai (Nuttall), the cause of Brazilian or 

 South American FOWL SPIROCHAETOSIS, was shown by Marchoux 

 and Salimbeni to be carried by Argas persicus. This has been corrob- 

 orated by Nuttall, Hindle, and others. Shellack transmitted the disease 

 by Argas re^exus (Fabricius) Latreille. In experiments conducted at 

 Hamburg, Fiilleborn and INIayer transmitted the disease by Ornifhodoros 

 moubata. Nuttall working with the Brazilian strain, found that when 

 the spirochaetes first enter the tick they soon disappear from the gut ; 

 a certain number degenerate while others traverse the gut wall and enter 

 the coclomic cavity to circulate all over the body. They enter various 

 organs, especially the cells of the iSlalpighian tubules and sexual organs, 

 in which they break up into a large number of small particles or coccoid 

 bodies which multiply by fission and give rise to large agglomerations. 

 These coccoid bodies may also be found in the lumen of the gut and Mal- 

 pighian tubules and in the excreta. According to Nuttall, the tick in the 

 act of feeding occasionally voids excrement and exudes a few drops 

 of secretion from the coxal glands situated in the first intercoxal space, 

 the fluid pouring out of a wide duct and being rapidly secreted from the 

 freshly imbibed blood serum. This fluid, as well as the salivary and intes- 

 tinal secretions of Argas, contains an anticoagulin. The coxal fluid dilutes 

 the escaped excrement and facilitates its getting into the wound inflicted 

 by the tick. This is doubtless the usual mode of infection, the coccoid 

 bodies in the excrement gaining access to the body of the host and after- 

 wards developing into spirochaetes, though the latter development has 

 not actually been followed. The bird begins to show symptoms after a 

 period of incubation of about four days following upon the bite of the 

 infected tick. 



