270 NATURE STUDY REVIEW [9:8— Nov., 1913 



This book is written especially for pupils in the elementary 

 schools and the ideas of evolution, heredity, variation, effect of 

 environment and the evolution of sex have been so skillfully con- 

 sidered in their relation to plant and animal life that the pupil will 

 acquire an intelligent understanding of natural development with- 

 out being troubled with any of the above terms. 

 ' " Teachers who have been at a loss to know how to approach this 

 subject will find in this book a guide which will enable them to pre- 

 sent such lessons in a satisfactory manner. Miss Torrelle has 

 demonstrated in practical work in public schools, that children are 

 greatly interested in the study of plant and animal life when it is 

 related to human life and its problems. We would recommend 

 this book to any teacher, parent or school board who wishes to teach 

 a series of lessons on life phenomena that will be rational and com- 

 prehensive. 



o. M. c. 



Mouth Hygene and Mouth Sepsis. John S. Marshall, M.D., 

 pp. XI -h 262. J. B. Lippincott Co., Philadelphia. $1.50. 



The author of this book was for a number of years a dental sur- 

 geon in the U. S. Army and probably has had the opportunity to 

 make a study of a greater ntunber of human mouths than has come 

 to any other American. His sincerity, professional insight, and 

 deep human interest are apparent on every page of his book. One 

 cannot rise from the reading of it without a profounder conviction 

 of the very great importance of oral hygiene, as a means of human 

 conservatives. 



Dr. Marshall quotes Dr. Osier as saying in an address to a group 

 of dental students. "You have just one gospel to preach. It is the 

 gospel of the cleanliness of the mouth; cleanliness of the teeth; 

 cleanliness of the throat. These three things must be your text 

 through life." This is the gospel that this book presents with 

 evangelistic fervor. In consequence, it is open to the criticism of 

 being too hortative in its style. It also abounds in descriptions of 

 individual cases as illustrations, and in excessive quotation. One 

 also feels that the attempt to be non-technical and at the same 

 time to adhere to technical terms results in a treatment unsatisfac- 

 tory both to the lay reader and to the dental technician. The 

 print is large and the page rather narrow, so that the book can be 

 read by the average reader in a few hours. 



F. M. G. 



