352 Forestry Quarterly. 



the knowledge of trees which the student has not opportunity to 

 see growing in the field. The schools in the North, for example, 

 find difficulty in giving instruction in the characteristics of the 

 species which occur in the far South or in the far West. The 

 schools in the West naturally have difficulty in giving knowledge 

 of the species which occur in the far East. Nevertheless it is 

 absolutely necessary that every student should have a working 

 knowledge by which to recognize the most important commercial 

 trees of the whole United States. This means a certain number 

 at each school which must be studied by the use of books, 

 herbarium specimens, photographs, lantern slides, etc., rather 

 than by actual observation in the field. These species can, how- 

 ever, be reduced to a relatively small number. 



There should be at least a thorough knowledge on the part of 

 the student of the distinguishing characteristics of the different 

 genera, and of the different groups, if any, within the genus. 

 Thus, it is important for the student to know the distinction 

 between the white oaks and the black oaks. He should know 

 thoroughly the characteristics of a few of the most important 

 commercial oaks of the country, but there can be no great ad- 

 vantage in requiring him to master all of the different species of 

 oak which occur. 



There are about 40 genera to be studied, and at least one species 

 in each of the genera should be mastered. In addition, the 

 student should be taught all species which can be found growing 

 in the locality of the school, and the most important species 

 carried in the lumber market. As an illustration, a school in 

 California should teach the local oaks. In addition, the students 

 should be taught the white, red, and chestnut oaks of the East, 

 but it is unnecessary to take the time to teach the long list of 

 other eastern oaks. In the same way an eastern school should 

 include in its course Abies concolor, magnifica, and grandis, but 

 the distinctions between the minor Abies seem unnecessary. It 

 should be kept in mind, that if the student knows the genera, 

 knows of the existence of the species in the genus, and is practised 

 in methods of analysis, he can quickly acquire the knawledge 

 needed in a new field. 



The time necessar}' for the work in descriptive dendrology is 

 set at 100 hours, including class, laboratory and field work. This 



