,^_ SOME NEW BOOKS. 153 



oak as a forest tree which has been so thoroughly investigated that 

 we may confidently accept it as typical." If the reader is absolutely 

 ignorant of scientific terminology, he will meet occasional stumbling- 

 blocks, but granted a slight knowledge he will find the book an 

 interesting and, for its size, a most thorough exposition of what is 

 known about this familiar tree. 



Chapter I. is introductory. Chapter II. deals with the acorn and 

 the germination of the seed, and includes, under an account of the 

 internal structure of the embryo, a clear definition of the cell as a 

 member of a tissue, that is, as part of a whole and separated from its 

 neighbour by a wall, which is a single structure common to both, 

 and not the result of the juxtaposition of two separate walls. Chap- 

 ters III. — VI. treat of the seedling and young plant. In Chapter III. 

 the structure and properties of the young root are considered. 

 There is a good explanation of the gradual development of the parts 

 in acropetal succession, and a description of the various expressions 

 of irritability to external stimuli, and their use to the organ in 

 functioning as a holdfast and a collector of nutriment from the soil. 



The following three chapters contain an account of the shoot- 

 system, that is, all the structures developed from the plumule, or bud 

 of the embryo. The arrangement of the skeleton of vascular bundles 

 is first described and the longitudinal course of the latter illustrated. 

 A chapter is devoted to the general outline of the stem, and excellent 

 figures of sections in different planes have been borrowed from Hartig 

 and Kny, though, unfortunately, the lettering by which the parts are 

 indicated is so broken and indistinct as to be often quite illegible. If 

 good figures are ready to hand, by all means let them be used ; but 

 surely there should be some method by which new lettering can be 

 introduced, for the parts, especially in longitudinal sections of vascular 

 tissue, are not always evident at first sight. The same remark applies 

 to some similar figures in Chapter VIII., and also to a revival from 

 Eichler's Blnthendiagramvie in Chapter IX., where after looking in vain 

 for X we find it to be an unknown quantity, and its place taken by a 

 broken-down 2. 



The buds and leaves are next described ; and there is a brief 

 and simple account of the process of transpiration and the function of 

 the green colouring matter, with its relations to sunlight and the assimi- 

 lation of food. . Here, as elsewhere, theory is avoided, the author 

 confining himself to mere statement of the physiological facts as 

 accounting for the various structures and tissue arrangement. 



In Chapters VII., VIII., and IX., headed " The Tree," the adult 

 root and shoot systems are considered with their mode of growth in 

 thickness and the consequent changes leading to the formation of 

 cork and bark. The interesting case of Symbiosis of the root and a 

 fungus, forming the Mycorhiza, is noted and figured, and an explana- 

 tion suggested. In Chapter IX. we are brought back again to the 

 acorn, by an account of the inilorescence, flower, and fruit. 



The next chapter is technical at times, giving in a short space a 

 concise account of the structure and industrial peculiarities of oak- 

 timber. The cultivation and the diseases and injuries to which the tree 

 is subject form the matter of Chapter XI. ; and Professor Ward must 

 have found it difficult to confine his remarks on this head to a dozen 

 pages, about half of which are occupied by some capital figures. 



Finally, the relationships of the oak and its distribution in space 

 and time are disposed of in less than five pages. The genus Quercns 

 is of interest, in containing numerous closely connected varieties, a 



