238 
Psyche 
[December 
Interpolated through this part of the book are numerous labora- 
tory and field exercises, which cover a wide variety of subjects 
and material, much wider than it would be possible for the aver- 
age class or teacher to complete, even during the summer time. 
It should be easy, however, to select a part of the exercises for 
which material and time might be available. 
C. T. Brues. 
