272 KATHARINE FOOT. 



cannot therefore be listed as an actual immune case. As stated 

 in my report " the death rate for the ten days feeding is certainly 

 abnormally high. Of the 36 used for the experiment 26 died 

 and as most of these died before the second moult and several 

 died while moulting, the facts seem to indicate that Du R.'s 

 blood does not nourish the lice normally but it does not warrant 

 assuming that it adequately explains his apparent immunity." 

 Unfortunately his case could not be further investigated as his 

 duties called him from Paris. 



I am now having a search made among the French families 

 that are infested, hoping to find one in which a member is im- 

 mune, for such a case would be a rare chance for experiment. 



It is humiliating to admit that the above report of a two years' 

 fight with P. vcstimcnti seems to leave the louse the victor, but 

 this war is not over nor is there the impediment of an armistice 

 for many earnest investigators are still fighting the pest and this 

 encourages further effort. 



APPENDIX. 



The following reports were written for the American Red 

 Cross while I was connected with the research department; 

 as further experiments with drugs and also with so-called im- 

 munity are still in process the details of these reports may be of 

 value for comparison with further results. 



On the Reaction of Lice to Quinine in the Blood of the Host. 



Host: Julienne F., age 30 years. 



Quinine: Quinine sulphate. Prescription by Col. R. P. Strong. 

 15 grains daily. 



No. of Lice: 3 J 1 , 3 ?, collected from a healthy woman at St. 

 Louis Hospital, January 30, 1919. 



Feeding: One hour daily. The above three pairs were kept 

 from February I to February 12 and during that period were 

 seen to mate six times. No. of eggs deposited, 69. No. of eggs 

 hatched, 38 (55 per cent.). (Normally more than 75 per cent, 

 of this generation are hatched.) Ten of the above generation 

 fed one hour daily from February 13 to March 5 (21 days). Bit- 

 ing during the hour was less frequent than normal and for much 

 shorter periods. The nymphs were very restless, making fre- 



