147 



the last row but one received very little recognition anywhere 

 until the last decade of the nineteenth century (and even yet 

 very little attention has been paid to them in some of the 

 older states where botanists are most numerous). 



The best order for teaching these sciences in a complete 

 botanical course — if such a course is ever given — is not so 

 obvious, principally because a course of instruction cannot very 

 well proceed in two directions simultaneously, but must follow 

 rows, or columns, or first one and then the other. Perhaps the 

 best way around this difficulty would be to subdivide the field 

 along horizontal lines into several parts, and then take a column 

 at a time, transgressing the upper or lower limits occasionally 

 to make certain points clearer. Then too it is customary to 

 teach along with the pure sciences more or less of certain applied 

 sciences or arts which have no place in the table, such as eco- 

 nomic botany, forestry, plant breeding, and agriculture. 



It will be observed that systematic botany or taxonomy, 

 which was once the largest feature in botanical text-books, is 

 absent from the table. Classification is not peculiar to plants 

 or organisms of any kind, and in itself is not a science at all, but 

 rather an art, a method or a convenience. The earlier classi- 

 fications of plants were very artificial and not scientific, but the 

 scientific basis of modern taxonomy is phylogeny, which has its 

 proper place in the table. 



Some botanists are inclined to regard physiology and ecology 

 as essentially one, while others have difficulty in drawing the 

 line between ecology and geography.* But the above table and 

 explanation should make the relations between these three 

 sciences clear. Although they are more or less interdependent, 

 they consider plants from three fundamentally distinct points of 

 view. Plant sociology, which is sometimes regarded as a part 

 of ecology, is still more distinct. 



It is scarcely necessary to remark that the sciences dealing 

 with the animal kingdom in general and those dealing with man- 

 kind in particular could be classified in a very similar way. 



* Human ecology and human geography have been even more persistently 

 confused than the corresponding botanical sciences, and a great deal of modern 

 so-called geography is nothing but ecology. For additional notes on the scope of 

 geography see Science II. 38: 816. Dec. 5, 1913. 



