2 
Book REVIEWS 163 
is done in a great many of the older elementary text-books. In parts 
relating to structure, the newer conceptions of anatomy are followed. 
Part III is designed to serve as an introduction to field work, and to 
a knowledge of the more interesting and important biological and 
economic aspects of a few important families and species among the 
spring plants. There is a considerable discussion of trees and their 
importance to man, and the main problems of forestry are emphasized 
by examples of the life of a few selected species of forest trees. The 
herbaceous monocotyledons, and the dicotyledons are studied from their 
biological and economic aspects, and their treatment is designed to 
serve as a guide for studies in other species. 
Throughout the text the plants are presented as living organisms, * 
comparable to animals, and with similar physiological life functions. 
The purely technical portions are linked up with the theoretical and 
economic aspects of the subject in a manner that brings the information 
home clearly and definitely. The treatment of hybridization and kindred 
subjects is as good as it is uncommon. The chapters on plant physiology 
are summarized and closely correlated with the seasonal life of such 
common plants as the bean, clover, and locust. Physiological processes 
are thus made directly applicable to seasoned life of species that very 
one knows, and can study. 
Mechanically the book leaves little to be desired. The paper, press- 
work, and binding are excellent, and the book will not come to pieces 
at once when placed in the student’s hands. The illustrations, both 
from photographs and drawings, are numerous, good, and excellently 
chosen. ; Me de A. 
THE NEW STONE AGE IN NORTHERN EUROPE. By John M. Tyler. 
Charles Scribner’s Sons, 1921. $3.00. 
Henry Fairfield Osborn produced a bookon the menthe Old Stone Age; 
Dr. Tyler has done the same for those of the New. He begins at the 
point where Osborn left off, and carries man on to the dawn of his- 
tory, taking up in detail the migrations, cultures, daily activities, and 
existing relics of these ancient ancestors of ours. 
Where and how man originated is still pretty much of question. We 
know that the earliest remains of man-like animals are found in south- 
ern and southeastern Asia. In those same regions today are the great 
apes that are probably descended from the same ancestors that gave 
rise to man. From the first ape-man to the high types of the Old Stone 
Age is a long step, but as Dr. Tyler is concerned mainly with the des- 
cendents of the Old Stone people, he covers it rather briefly. 
The change from the age of the chipped stone implements to that of 
polished ones took place in northern Europe about fifteen to twenty 
thousand years ago. Researches in Asia indicate that there the transi- 
tion was considerably earlier, and that the New Stone men migrated 
westward from the region of the Iranian plateau. However that may 
be, the relics of the shell heaps of Denmark and Scandinavia show 
that some thousands of years after the Cro-Magnon people made their 
