Probably the most important science for the forester is plant 

 sociology, which has hardly been recognized as a distinct science 

 as yet. (In schools of forestry it is commonly taught along 

 with tree physiology and ecology under the name of silvics.) The 

 fact that scientific forestry involves something not adequately 

 provided for in existing classifications of science is doubtless 

 what led the writers referred to to claim recognition for it as a 

 science. As the forest is the highest and most complex expression 

 of social plant life, and consequently the phenomena of plant 

 sociology are best exemplified in a forest, as both Zon and Graves 

 clearly recognized, it is quite natural that many of the laws of 

 this nascent science should have been discovered some time ago 

 by observing foresters in the course of their work. One of the 

 best popular treatises on plant sociology (though it was not called 

 by that name at the time) was published seventeen years ago 

 by a well-known forester.* 



But the term "plant sociology" cannot be rejected on the 

 ground that it is merely a laterf synonym of one phase of forestry, 

 or of silvics. For forestry deals with trees only, while plant 

 sociology deals with vegetation of all kinds. Neither is it a mere 

 branch of ecology; for although the plants surrounding any 

 given plant may be regarded as part of its environment, vegeta- 

 tion types can be studied and classified regardless of environment. 

 It is not the purpose of this paper to discuss the manifold phe- 

 nomena and problems of the new science, but it will be appro- 

 priate to state that probably the most complete and scholarly 

 work on the subject yet published is Clements's "Development 

 and structure of vegetation," which constitutes the seventh 

 monograph of the Botanical Survey of Nebraska, 1904. (This 

 contains abundant references to the literature of the subject, 

 and sketches its historical development. Most of the same 

 ground is covered in "Research methods in ecology," by the 



* Pinchot's Primer of Forestry, part i. Washington, 1899. 



t The first use of the term that has come to the writer's notice is by Dr. Charles 

 E. Bessey in Science II. 37: 4. Jan. 3,1913; but he there confused it with ecology. 

 The writer used it in Science II. 38: 818. Dec. 5, 1913; Torreya 13: 139; 14: 145, 

 147; Rep. Fla. Geol. Surv. 6: 176. Dec. 1914:7: 181. Sept. 1915; and contributed 

 a brief note on it to the second edition of the New International Encyclopaedia 

 (New York) 18: 705. Feb. 1916. 



