Reviews and Notices of Booh, 459 



He was led in the course of his enquiries, to the study of Forbes's 

 famous work on the Alpine Glaciers. The phenomena observable 

 in these masses of moveable ice led him to suppose that possibly 

 they might afford a solution of the problem of slaty cleavage in 

 rocks. This he endeavours with singular clearness and force to 

 show. The conclusions to which he arrives are, that cleavao;e in 

 the glaciers at angles to the planes of their surfaces is due to the 

 immense latteral pressure to which they are subjected. This 

 ascertainable fact he applies to the cleavage of stratified rocks at 

 angles to the planes of stratification. The attention of other ob- 

 servers has been directed to'the same subject and from experiments 

 and observed facts we are in a fair way of arriving at certain con- 

 clusions regarding the nature and causes of slaty cleavage. 



This book is written in a fine, frank, manly style. With great 

 simplicity and beauty it combines in a successful manner the pop- 

 ular and scientific in the treatment of its topics. To our youth, 

 and to those of riper years, furnished with the education which our 

 schools and colleges afford, we can recommend this book with 

 confidence that they will find it most interesting and profitable 

 reading. a. f. k. 



What may he Learned from a Tree. By Harland Coultas. 

 New York : D. Appleton & Co. Montreal : B. Dawson & 

 Son. 



This book is respectfully dedicated to all lovers and friends of 

 nature. The author's intention is to show what may be learned 

 from a tree physically and analogically. He traces its life-his- 

 tory from the first manifestations of vitality in the germinating 

 seed until the period of puberty when it puts forth flowers and fruit ; 

 he also considers its phenomena after it has passed its prime ; and 

 shows its appointed limits, in virtue of the physiological law 

 which governs the development of its organisms in common with 

 those of all other plants. 



The author aims at writing a popular book ; he addresses him- 

 self to the people, — those who feel life to be one continued strug- 

 gle for existence. The style is rather popular and eloquent for 

 our taste, we would prefer greater clearness and simplicity and 

 less diffuseness of style and treatment. The object of the work is 

 creditable, the author's acquaintance with vegetable physiology 

 seems accurate and considerable, and his treatise may be read 

 with much interest and profit. 



