6 NORTH AMERICAN ANOPLURA 



cificity of the blood of different mammal kinds, and the physiological 

 (chemico-physical) similarities of the blood of nearly related mammals 

 as contrasted with the dissimilarities of the blood of widely related kinds, 

 finds an interesting confirmation in the very precise host relations of the 

 blood-sucking parasites of the mammals. 



As a corollary of this precision of host-relation, there arises the pos- 

 sibility of the determination of the phyletic relationships of hosts on a 

 basis of the identity or close relationship, or the non-identity or wide rela- 

 tionship, of their Anopluran parasites. For the proper following up of 

 this interesting matter, however, a much wider knowledge of the Ano- 

 pluran fauna is needed. 



The importance from the economic and medical point of view of a 

 knowledge of the blood-sucking parasites of mammals is, of course, ap- 

 parent when we consider the new knowledge of the dissemination (and 

 in some cases, incubation) of various germ-caused diseases. The Ano- 

 plura have already been tried and convicted of participation in this crime 

 of aiding and abetting the germs of animal and human disease in their 

 struggle for distribution. And they have been proved to be very sus- 

 picious characters, at least, if not yet known to be actual criminals, in 

 relation to their possibility of serving as true alternate hosts of certain 

 dangerous Sporozoa. At least some of these parasitic and disease-pro- 

 ducing Sporozoa can enter, remain in, and pass from the bodies of the 

 sucking lice with unimpaired life and virulence. 



The Anoplura, then, call insistently for study; and the first need in 

 that study is the collection of material from many hosts and the careful 

 systematic determination of this material. We need to know how many 

 and various are the living species of the group, and the exact facts of 

 their geographic and, especially, host distribution. The present paper is 

 a small contribution along this line. 



