x PREFACE TO THE ENGLISH EDITION 



it should be remembered that, in the first place, the student's 

 attention is not here directed to the fungus itself, as an object 

 of morphological study, so much as to the action of certain 

 fungi in inducing specific diseases in trees ; and, in the second 

 place, it is assumed that the student is already acquainted with 

 the main facts in the biology of the fungi including their 

 morphology before he attempts this particular branch of 

 science. 



Again, the professed botanist may remark how much is 

 assumed concerning the structure and physiology of the host- 

 plants the trees whose diseases are here treated of. The reply 

 is, as before, the student cannot extract all, or nearly all, of 

 value from such a work as this, unless he is thoroughly 

 acquainted with the principal facts of the normal anatomy 

 and physiology of the higher plants. 



A third platform of criticism is that of the " practical 

 forester," who may object that the author gives too little 

 information as to the details of combative or therapeutic 

 treatment of the special diseases. To this the obvious reply 

 is that it is not necessarily the duty of the scientific pathologist 

 to devise the particular mode of attack to be employed in 

 special cases these plans of remedial treatment involve the 

 outlay of money, labour, &c., which vary in different countries 

 and in different cases, and enough has been done by the in- 

 vestigator who indicates the factors involved. Special works 

 must be consulted regarding the details of treatment, though it 

 seems to me the author, while clearly recognising this, goes even 

 out of his way to give practical hints as to treatment, and has 

 in many cases put the principal factors concerned in the treat- 

 ment so clearly that every thinking practical man can do the 

 rest himself. No better illustration of the thoroughly practical 

 nature of his writings could be selected than his recommenda- 

 tions for the treatment of Dry-rot. 



But it is by no means solely on the ground of the information 

 capable of direct application which the book contains that it 

 should be judged. I would especially urge the value of this 



