SPIEOCHAETA PERTENUIS 495 



for thirty minutes. Small pieces of rabbit kidney are then 

 pushed to the bottom of the tubes and the incubation 

 must be carried out anaerobically. 



It is probable that the spirachaetes of relapsing fever 

 in different countries are distinct species. 



Spirochaeta Duttoni. Found in the blood-plasma in 

 African relapsing, or tick, fever. It closely resembles 

 the S. recurrentis, but is more readily inoculable into 

 rats, mice, and guinea-pigs, and the one does not protect 

 against the other. It is conveyed by a tick, Ornithodoros 

 moubata, the malpighian secretion of which is the principal 

 infective agent. The eggs of infected ticks are also in- 

 fected, and the infection may be transmitted to the third 

 generation of ticks. 



Duval and Todd l state that multiplication of S. Duttoni 

 takes place in vitro in a culture medium made with hens' 

 eggs and mouse blood. Leishman believes that certain 

 chromatin bodies present in the eggs and nymphs of the 

 ticks are the developmental forms of the spirochaetes. 



Blood spirochaetes have been found in many animals, 

 e.g. cattle (S. Theileri), mice (S. muris), fowls (S. galli- 

 narum), and geese (S. anserina). 



Spirochaeta pertenuis. Castellani 2 found in the 

 yaws (frambcesia) granulomata a delicate spirochaete 

 resembling the S. pallida of syphilis closely, but even 

 more delicate and difficult to stain than the latter organism, 

 and named the S. pertenuis. It is present also in the 

 spleen and lymphatic glands in the disease and in inoculated 

 monkeys. Rabbits can be inoculated in the testicle and 

 Noguchi has obtained cultures. 



Some observers have supposed yaws to be a manifesta- 

 tion of syphilis, but (1) syphilitic patients can be inoculated 

 with yaws ; (2) syphilis may supervene on yaws ; 



1 Lancet, 1909, vol. i, p. 834. 



2 Brit. Med. Journ., 1907, vol. ii, p. 1511. 



