60 



on the ninth and tenth days after the infecting meal and not before 

 this. (2) The excreta of these same hce are infectious from the above 

 time onwards. (3) Two attemps to reproduce typhus experimentally 

 with the offspring of infected (and viralent) lice, proved negative. 

 Heredity of infection is not a proven fact in the case of 

 the louse and it does not appear probable. (4) Bacterial forms, 

 identical with those described by Edm. Sergent and his collaborators 

 from lice fed on typhus patients, have been found in a similar proportion 

 in lice taken from the inhabitants of a non-infected country. (5) Two 

 experiments on the filterability of the exanthematous virus contained 

 in infected lice have given only uncertain or incomplete results. 

 (6) The guineapig can almost completely replace the monkey in the 

 study of exanthematous typhus ; it is suitable for the purpose of 

 keeping the virus in the laboratory. (7) The spleen of infected 

 animals is virulent, but not to a more marked degree than the blood. 

 The association of heterogeneous serums with the exanthematous virus 

 (blood) appears to diminish the resistance of the guineapig, but not 

 in a manner useful for experiments. (8) A previous attack of spir- 

 illosis sometimes protects the monkey against the effect of a 

 subsequent inoculation with exanthematous virus ; this resistance is 

 perhaps nothing more than the effect of the recent inoculation of the 

 blood elements. (9) Further attempts to reproduce exanthematous 

 typhus in the rabbit, dog and cat proved negative. 



Regulations of the Montana State Board of Entomology.— is« Bienn. 

 Rept., Montana State Bd. Entom., 1913-14, Helena,I)ecembev 1914, 

 pp. 12-15. [Received 27th March 1915.] 



The Montana State Board of Entomology has issued regulations in, 

 connection with the control of Dermacentor venustus, the carrier of 

 Eocky Mountain spotted fever in the Bitter Root Valley. They 

 provide for the division of the area into tick-control districts, for 

 the erection of a dipping- vat and yards in each district, for a close 

 quarantine of all domestic animals which are not dipped, and for the 

 issue of permits without which no domestic animal (including cows, 

 horses, asses, mules, sheep, goats, and hogs) may be removed from 

 the districts in question. 



King (W. V.). Worlc of Bureau of Entomology against Spotted Fever 

 Tick in co-operation with Board. — 1st Bienn. Rept., Montana State 

 Bd. Entom., 1913-14, Helena, December 1914, pp. 16-27. 

 [Received 27th March 1915.] 



The U.S. Bureau of Entomology has established three control 

 districts against Dermacentor venustus in the northern end of the Bitter 

 Root Valley. The instruction of the public as to the part played 

 by the tick was an early phase of the work. The control programme 

 may be outlined as follows : — the destruction of adult ticks on domestic 

 animals ; the destruction of native rodents ; the burning, clearing, 

 and development of land ; the construction of dipping vats. Should 

 the practical difficulties in destroying the ticks on domestic animals 

 be overcome, it is still thought that this method, which was 



