1898.] MICROSCOPICAL JOURNAL. 217 



icteroides, these other organisms proceed at once to kill 

 off the icteroides. By inoculation, Sanarelli produced a 

 disease much resembling yellow fever, but the analogy 

 was not so strong as desired. The symptoms and patho- 

 logical changes differed sufficiently from those produced 

 by other organisms to warrant the belief that the yellow 

 fever was actually produced. Serum from convalescents 

 or from yellow-fever cadavers produced only slight 

 agglutination of the icteroides. Antidiphtheritic serum 

 produces rapid agglutination of the bacillus, which would 

 indicate a close biological relationship between it and the 

 Klebs-Loeffier bacillus. There are points of resem- 

 blance in the manner in which the infection of yellow 

 fever and diphtheria spread. Typhoid serum also pro- 

 duces this phenomenon but partially, and, as would be 

 expected, colon serum and that from normal man pro- 

 duces no effect. Serum from a convalescent possesses 

 no curative action in the guinea pig simultaneously with 

 the minimum fatal dose of icteroides, but 2 c. c. of the 

 same serum administered 24 hours previous to the 

 minimum fatal dose seems to confer immunity, — at least, 

 the pig does not die. A horse has been immunized to the 

 icteroides and .5 c. c. of his serum will give to the 

 guinea pig the immunity above mentioned under the 

 same conditions, and even after 48 hours has been allow- 

 ed to elapse, 2 c. c. will save the animal. Saranelli 

 used the serum of a horse inoculated with gradually in- 

 creasing quantities of the icteroides for 18 months. In 

 Brazil, he treated 8 cases with subcutaneous injections, 

 the total quantity varying from 15 c. c. to 65 c. c. with 

 a mortality of two. Many able and conscientious inves- 

 tigators are still working to veriiy the researches of Sana- 

 relli and it is hoped they will succeed at an early date. 



V^olle's Diatomaceae of North America with plates for 

 sale cheap. Address the Editor. 



