30 THE AMERICAN BOTANIST 



studies and includes the care and breeding of animals in the 

 general subject. The book, however, is not one to which the 

 teacher can go for directions for carrying on the work of teach- 

 ing; it is rather a discussion of all sides of the subject from 

 which any teacher should gain man)'^ new ideas. The book is 

 published by the Macmillan Company at $1.00 net. 



The teacher of botany, v/lio, under the demand for agri- 

 culture, has been obliged to add this subject to the course, will 

 be glad of a little "Manual of Agriculture" by D. O. Barto, 

 of the University of Illinois, issued by D. C. Ht-ath & Co. This 

 contains thirty-six exercises, mostly experiments, with more or 

 less comment, explanation or direction for each. In the opin- 

 ion of the reviewer, the book deals with me subjects most 

 worth while in a course of agriculture, and the only adverse 

 criticism that can be offered is that in the experimental part. 

 too little is left to the investigation of the student, a tendency 

 common in many school books, where the edge is taken off the 

 pupil's interest by telling him how the work will come out. 

 The price of the book is 50c, 



There are two main theories to account for the origin of 

 the higher types of plants. While everybody now agrees that 

 the more complex type have arisen from simpler forms by some 

 process of evolution, everybody does not agree as to the exact 

 path along which this evolution has progressed. The older 

 theory holds that beginning with the algae, the family line runs 

 through the mosses from some alga ancestor and suggests the 

 origin of the ferns from some such liverwort as Anthoceros. 

 The newer theory derives the ferns from the algae direct, and 

 makes the mosses their degenerate descendants. Prof. D. H. 

 Campbell, however, holds to the older theoiy and in a recent 

 book entitled "Plant Life and Evolution" presents the facts 

 anew for this theory. Although it is the phase of evolution 

 most frequently presented in the class room it has gained a new 

 interest from the lucid and informing style of the author and is 



