144 
Psyche 
[June 
every form; but the present location of the types is omit- 
ted in most cases. The descriptions are clear and the 
many illustrations of details, comparing closely allied 
forms are most commendable. 
Only 12 of the 302 fleas listed from America north of 
Mexico extend across the continent; and this number 
dwindles to 5 (one of them doubtfully in the East) after 
eliminating 7 species introduced from the Old World by 
man. The eastern flea fauna is, moreover, scanty, only 
56 species and subspecies being known from east of the 
100th Meridian, as against 236 from the western area. 
The explanation lies, of course, in the extremely poor 
mammalian fauna of the eastern area. The author has 
relied too exclusively on Irving Fox’ book (1940) for his 
information on eastern fleas. H. S. Fuller in 1943 raised 
the number of species known from Vermont to 15 (not 
one, as stated by Hubbard), and recorded 9 species from 
West Virginia, from which state Hubbard says there are 
no published records. 
In the careful and elaborate analysis of host relation- 
ships, the notes on the characteristics and behavior of the 
several types of hosts will be particularly useful. The 
relations between blood-sucking ectoparasites and their 
hosts are not merely those of taking and giving food. 
The parasite’s structure, life-history and behavior are in 
most cases closely correlated with those of the host. The 
author’s detailed information on the relative abundance 
of the several species of fleas often found on the same host 
may help to determine the normal or breeding, and the 
accidental or stray hosts of each species, leading even- 
tually to the study of the factors determining the choice 
of the host. 
The author is to be congratulated on his book, which 
crowns some fifteen years of field and laboratory work 
carried on with unusual enthusiasm. — J. Bequaert 
