THE OAK. 187 



popular introduction to forest botany,' ' one chapter only is devoted 

 to the cultivation of the tree, and the book may be better described 

 as a short account in fairly simple language of all that is most 

 interesting in the life of an oak from its starting point as the tiny 

 embryo still protected in the acorn to the stately forest tree which 

 may live a thousand years. There are a goodly number of illus- 

 trations, about fifty, many of which we recognise as old friends. 

 The frontispiece is a fine representation of the oak in summer, 

 while the oak in winter forms another plate facing page 8 ; both are 

 after Eossmassler. The wbrks of R. Hartig, Kny, Luerssen, and 

 Miiller have supplied figures of sections of the stem or wood and 

 bark ; one of the nicest in the book is that on p. 53, a transverse 

 section of the young stem, after Hartig. The parts are here very 

 well shown, but the explanatory letters have in many cases almost 

 disappeared, or are quite illegible ; and we notice the same in many 

 of the borrowed figures, a serious inconvenience when dealing with 

 such complicated structures as sections of wood. 



The plan of the book is a series of object-lessons. First the acorn, 

 the fruit with the seed inside, is described, and the parts of the 

 embryo, their structure, and function are clearly explained. Next the 

 seedling and young plant are considered, and successive chapters 

 devoted to the root, the distribution of the tissues in the shoot, the 

 structure of the vascular tissue, and lastly the buds and leaves. 

 Then the parts of the adult tree are discussed in the same order, 

 followed by an account of the inflorescence, flowers, fruit, and seed. 

 A chapter is given to the timber, u its structure and technological 

 peculiarities," another to the cultivation of the tree and the diseases 

 and injuries to which it is subject, and the twelfth and last deals 

 with " the relationships of the oaks, and their distribution in space 



and time." 



The purely botanical part is undoubtedly the best. The corre- 

 lation of histology and physiology, the explanation of structure by 

 the function of the parts or the organ as a whole is admirable. 

 Theory is avoided, and the facts are clearly stated. We may refer, 

 for example, to the description in Chapter vi. of the leaves and 

 their function as organs of transpiration and assimilation. More- 

 over, each member is considered not merely as part of the seedling 

 or adult oak, but as a typical plant member. Thus, in dealing with 

 the root, we are told in what respects it is a typical root, while in 

 the comparison of the structure of the seedling and older plant we 

 have an account of the mode of growth in thickness of the ordinary 



dicotyledonous stem and root. 



Interesting biological points are also noticed. The common 

 occurrence of a Mycorhiza is referred to, and explained up to date:— 



» . 



ymb 



and the root is of advantage to the oak. It has even been suggested 

 that the mycelium performs the functions of root-hairs to the root, 

 absorbing water and nutritious material from the soil, and passing 

 them on to the oak, in return for a certain small proportion of 

 organic substance which the latter can well afford." 



The chapter on the timber contains much interesting mforma. 



