128 THE ANIMAL PARASITES OF MAN 



Castellan! and others have shown that monkeys successfully 

 inoculated with syphilis do not become immune to yaws, and vice- 

 versa. 



Craig and Ashbtirn, using the monkey Cynomolgus philippincnsis, 

 found these animals susceptible to yaws but not to syphilis. 



The ulcerated lesions of frambcesia are rapidly invaded by 

 numerous bacteria as well as by different spirochaetes, of which 

 Castellani has described three distinct species. One is identical 

 with Spirochceta refringens, Schaudinn, the other two are thin and 

 delicate. One, S. obtusa, has blunt ends ; the other S. acuminata, has 

 pointed ends. T. pertenue is also present. 



The reasons for considering T. pertenue to be the specific cause of 

 framboesia are : 



(1) T. pertenue is the only organism present in non-ulcerated 

 papules, in the spleen and in the lymphatics of yaws patients, or 

 of monkeys artificially infected with the disease. By no method 

 has any other organism been obtained. 



(2) Extract of frambcesia material, free from all organisms other 

 than T. pertenue, reproduces the disease if inoculated. 



(3) Extract of frambcesia material deprived by filtration of 

 T. pertenue is no longer infective on inoculation. 



The method of infection is contaminative, by direct contact. 

 Women in Ceylon are frequently infected by their children. Any 

 slight skin abrasion is sufficient to admit the parasite. In some 

 cases, insects may carry the disease from person to person, and even 

 in hospitals, when dressings are removed, it has been noticed that 

 flies greedily suck the secretion from the ulcers. T. pertenue has 

 been recovered from flies that have fed on yaws, and monkeys have 

 contracted the disease when flies were placed and retained on them 

 for a short time, after the insects had fed on yaws material. 



CULTIVATION. T. pertenue has been cultivated by Noguchi, who 

 finds three types of parasites in his cultures, as before mentioned. Its 

 multiplication is by longitudinal division. 



Noguchi 1 (1912), has cultivated species of Treponema from the 

 human mouth, e.g., T. macrodeutinm, T. microdentinm and T. mucosnin, 

 the latter from pyorrhea alveolaris. These parasites in the past may 

 have been confused under the name Spirochceta dentium. 



Class III. SPOROZOA, Leuckart, 1879. 



The third group of the Protozoa consists entirely of parasitic 

 organisms forming the class known as the Sporozoa or spore- 

 producing animals. The members of this class are characterized 



1 fonrn. Exptl. l\Ied. t xv, p. 8 1 ; xvi, p. 194. 



