418 SANITARY ENTOMOLOGY 



and Dermacentor nit ens Neumann. It is also recorded from Hyalomma 

 aegyptium (Linnaeus) Koch by Carpano (1915) and Dermacentor reti- 

 culatus (Fabricius) Koch (Doflein 1911). The ticks do not produce an 

 infection during the first two days after they liave taken up the infective 

 organism. They may transmit the organism in the instar following that 

 in which they ingested the blood containing the organisms. 



Mastigophora: Spirochcctacea: Spirochostidce 



Spiroschaudinnia sp. {duttom Brumpt, not Novy and Knapp), the 

 cause of ABYSSINIAN RELAPSING FEVER, was transmitted by 

 Brumpt to monke3's, rats, and mice by means of Ornithodoros savignyi 

 (Audouin) Koch. 



Spiroschaudinnia anserina ( Saccharoff ) , the cause of GOOSE 

 SPIROCHAETOSIS, Transcaucasia, is carried by Argas persicus 

 (Oken) Fischer Von Waldheim (Saccharoff 1891). 



Spiroschaudinnia duttoni (Novy and Knapp), the cause of RE- 

 LAPSING FEVER of tropical and west Africa, is hereditarily trans- 

 mitted by Ornithodoros inoubata (Murray) Pocock. The transmission 

 by this tick was first proven by Dutton and Todd in 1905. Many others 

 have corroborated this. Mollers in 1907 showed that infected ticks, fed 

 successively on six clean animals, after each feed may lay a batch of 

 infected eggs. The ticks hatched from these eggs are capable of con- 

 veying the infection to the animals they feed upon. Moreover, not only 

 is the infection carried through the second generation, but also through 

 their offspring, ticks of the third generation being found to be infective 

 even though their parents have never fed on an infected animal. Schuberg 

 and Manteufel (1910) and Hindle (1911) found that about 30 per cent 

 of the ticks are immune to spirochaetal infection. In man the parasite 

 is ribbon-shaped on transverse section and though it is in spirals, may 

 be simply waved. A narrow undulating membrane is sometimes present. 

 Reproduction is by longitudinal as well as transverse fission and also by 

 granular formation. The latter method occurs just before the crisis, 

 w^hen the blood is swarming with parasites. They are then to be seen 

 coiling themselves up in the spleen, bone marrow, and liver, and becoming 

 surrounded b}'^ a thin cyst wall. In this cyst the parasite becomes more 

 and more indistinct and breaks up into filterable granules. 



Leishman found that when the organism finds its Avay into the intes- 

 tinal sac of the tick it loses its mobility and characteristic appearance, 

 and chromatic masses escape into the lumen of the gut in the form of 

 small rods or rounded bodies. These multiply and pass into the cells of 

 the Malpighian tubules. Hindle found the spirochactes always present 

 in the gut of infected ticks, often in the Malpighian tubules and sexual 



