692 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The bacillus is pathogenic to guinea-pigs and frogs, the former 

 dying in 10-15 days after intraperitoneal injection. At the site of 

 inoculation an ulcerating papule torms, with swelling of the neighbour- 

 ing glands. The bacillus is agglutinated by the serum of syphilitic 

 patients. 



Bacilli in Syphilitic Semen.* — Max Joseph and Piorkowski ex- 

 amined bacteriologically the semen of 22 syphilitic patients, employing 

 pieces of fresh normal placental tissue as their culture-medium ; these 

 were previously observed in sterile Petri dishes and contaminated por- 

 tions rejected. Sterile pieces were inoculated with freshly ejaculated 

 semen and incubated at 37° C. In every case transparent dewdrop-like 

 colonies of bacilli appeared on the first day, which later became grey 

 and confluent. The bacilli were broad and granular, clubbed at one or 

 both ends like the Klebs-Loffier bacillus, and of about the size of the 

 B. subtilis. The bacillus stained best with carbol-fuchsin or gentian- 

 violet, also by Gram, but were not acid-fast. Polar staining involution 

 forms were noted in old cultivations. Sub-cultivations in broth failed, 

 but succeeded on solid agar or better still on serum-agar, the growth 

 appearing as a greyish-white waxy layer. In gelatin stab there was a 

 luxuriant whitish growth, and on potato a moist, glistening, whitish 

 layer. Milk was coagulated with the production of an acid reaction, but 

 no gas formation was noted. 



The bacillus was not pathogenic to guinea-pigs, rabbits, or mice. 

 No growth could be obtained from the semen of healthy non-syphilitic 

 men. The bacilli appeared to be related in some way to the sperma- 

 tozoa, for if the semen was kept a few hours until the spermatozoa were 

 dead, no growth could be obtained, and further, if no spermatozoa were 

 present in the seminal fluid, even when such was derived from cases of 

 recent syphilis, no bacilli could be demonstrated. 



Transmissibility of Plague to Bats.f — Gosio remarks that many 

 species of animals have been studied with regard to their susceptibility 

 to bubonic plague, rats and mice exhibiting spontaneous infection in 

 countries where plague is epidemic : whilst the field-mouse, guinea- 

 pig, rabbit, ape, cat, fowl, and sparrow have been infected experimen- 

 tally. The pigeon is susceptible when fasting, and the lizard and snake 

 if kept at a high temperature. The dog, ox, and hedgehog have so far 

 proved immune. At the time of the small epidemic of plague at Naples, 

 when the author was placed in charge of the sanitary department, no 

 public health statistics were available, but by instituting such statistics 

 the origin of the infection was traced to the warehouses of the Punto 

 Franco, where both rats and bats abounded, and although high walls 

 and an isolated drainage system prevented the egress of the former, these 

 precautions were obviously useless if the infection could be conveyed by 

 the bats. Gosio therefore inoculated the common bat ( Vesperugo noctula), 

 which is found throughout the greater part of Italy, with plague bacilli 

 isolated from the Naples epidemic and retained in a virulent condition 

 by passages through white rats. Subc\itaneous inoculations were prac- 

 tised, the dose at first employed being 0*5 ccm. of a 24-hour old broth 



* Med. Rev. Reviews, v. (1902) pp. 420-1. See also Berlin Klin. Woch., 1902, 

 pp. 257 ond 282. f Atti Reale Accad. Lincei, xi. (1902) pp. 448-9. 



