February,. ’23] 
REVIEWS 
101 
the Holland Phytopathological Service for many years, under the leader¬ 
ship of Dr. Ritzema Bos. International team work and cooperation 
between the economic entomologists and the phytopathologists is be¬ 
coming almost daily more important, and this fact is strongly realized 
in the United States, as is indicated by the extremely interesting sym¬ 
posia that have been held now for three years in succession by the Ameri¬ 
can Association of Economic Entomologists and the American Phyto¬ 
pathological Society; and it is greatly to be hoped that American ento¬ 
mologists and phytopathologists will be present at the coming con¬ 
ference. 
A notable fact connected with this announcement is that in its title 
phytopathology and economic entomology are coordinately mentioned. 
This, we think, is the first time that this has happened in the recent 
development of agricultural science in Europe. And it is a gcod step. 
The agricultural entomologists of several European countries have not 
thoroughly approved of the fact that they were considered as belong¬ 
ing to a subordinate branch of a phytopathological service, and have 
felt that their organizations should be explicitly designated as in¬ 
tended for the investigation of problems relating to phytopathology 
and economic entomology (or the reverse). In America, the economic 
entomologists have their own independent official organizations and 
their own independent societies, and Europe will undoubtedly come 
eventually to the same arrangement. This conference is notable, 
therefore, as the first step in this direction. It is interesting to note 
that in the founding of the Societe de Pathologie Vegetale de France the 
economic entomologists joined in for the reason that they were not 
sufficiently numerous in that country to start their own organization and 
have since been outvoted as to its title by the more numerous botanists. 
The whole subject has received a vigorous discussion in Germany, where 
the economic entomologists founded their own organization after the 
return of Escherich from America, three years before the World War. 
Reviews 
Entomology with Special Reference to its Ecological Aspects by J. W. 
Folsom. Third edition with five plates and 308 text figures, pp. I-VII, 
1-502. P. Blakiston’s Son and Co., 1922. 
The third edition of this standard work bears evidence of thorough revision, 
including a great deal of new material and a few new illustrations and like its prede¬ 
cessor has been reset. The chapter on “Classification" reflects the latest develop- 
