NOTES ON PEDICULUS VESTIMENTI. 265 



At intervals during a period of two years I have fed P. vesti- 

 tnenti on rabbits, guinea pigs, rats, mice, fowl, pigeons and 

 canaries. In addition to feeding them on the blood of these ani- 

 mals I have tried to give them human blood by inserting a small 

 piece of absorbent cotton under the most superficial layer of the 

 epithelium of a young white mouse and dropping a few drops of 

 fresh human blood upon the cotton. They bite the white mouse 

 readily and get the human blood, as was shown by initial experi- 

 ments with physiological salt solution stained with cosine the 

 colored solution in the alimentary tract demonstrating the pos- 

 sibility of their getting human blood by this method. A fresh 

 mouse could be used each day, avoiding the possible criticism of 

 the mouse itself becoming infected. Illness prevented my carry- 

 ing these experiments to a satisfactory conclusion and I therefore 

 do not know whether life can be much prolonged by this method. 

 It however justifies further experimenting, for it should be of 

 value in connection with those problems where it is imperative to 

 keep the lice alive for definite periods after feeding them with in- 

 fected blood. Further it should be of value in determining 

 whether the lice themselves are infected, or whether the infection 

 is confined to the blood in the alimentary tract, the latter acting 

 merely as a mechanical transmitter. Many authors believe that 

 this is the sole method of infection scratching the bite and thus 

 inoculating the victim with the feces of the louse being the sole 

 danger the bite alone being harmless. Nuttall ('17, page 61) 

 quotes one experiment where a man was bitten by fifteen thou- 

 and lice which had fed on a relapsing fever patient and a second 

 case in which a thousand lice were used. In neither of these 

 cases was the host infected. 



It is an established fact that the louse is the carrier of at least 

 three diseases. It has been demonstrated for typhus fever by 

 Nicolle ('09), Nicolle, Conte and Conseil ('10) and others. It 

 has been demonstrated for recurrent fever by Sergent and Foley 

 ('io), Sergent, Gillot and Foley ('n), Nicolle, Blaizot and Con- 

 seil ('12) and others. 



It has been demonstrated for trench fever in the Report of the 

 Medical Research Committee of the American Red Cross. 



In addition to the above mentioned established cases lice have 



