CHAPTER V. 



STUDY OP PATHOLOGY. 



WHILE sylviculture is based upon a knowledge of the 

 physology of arborescent vegetation, it is found to be 

 necessary to the attainment of the best results, that the 

 forester should have some knowledge of the diseases to 

 which different forest trees are liable the nature, the 

 symptoms, and the causes of these ; and to the study of 

 those great attention is given by the students of forest 

 science. 



In the museum of the Prussian Forest Institute at 

 Eberwalde, the impression produced upon the mind of the 

 visitor is that there are there specimens representative of 

 every disease to which trees are heir, specimens exhibi- 

 ting the progress of the disease from the attack to the 

 consummation ; and hard by, the bark, the wood, the insect, 

 or the parasitic herb or fungus by which it has been 

 induced : the insect and the fungus being exhibited 

 under all the transformations through which they pass ; 

 while specimens of the effects of lightning and other 

 physical causes of the decay or destruction of trees are 

 not alacking. 



And similar collections sufficient to afford facilities for 

 the study of the diseases of trees, and of means of 

 preventing or of remedying the evils done are to be found 

 in many other similar institutions. 



In an introduction to the study of modern forest 

 economy it is only an illustration which is called for, or 

 can be given. In selecting one I confine myself to a 

 notice of fungi infesting the Austrian or black pine, of 

 the culture of which some account has just been given, 



o 



