176 BIOLOGICAL LECTURES. 



upon the question now under consideration that we may well 

 be justified in regarding this notable work as marking the real 

 beginning of a new feature in systematic botany. 



During the next thirty years little real interest appears to 

 have centred in this question, although within that period 

 there were issued a number of papers upon subjects having a 

 more or less direct bearing upon it, and the necessity for some 

 more critical method of distinguishing woods under all condi- 

 tions incidental to their economic application was made evident 

 by the treatise issued by H. Nordlinger for the use of forestry 

 students. 1 



Fully twenty years ago De Bary, in summarizing the results 

 already reached by Goppert, Hartig, Nordlinger, and others, 2 

 gave a clear exposition of the general basis upon which such a 

 classification might be constructed. 



It was not until 1880, however, that special attention appears 

 to have been directed to the desirability of such a line of inves- 

 tigation being taken up seriously. In that year the Vienna 

 Academy proposed, as a subject for the Baumgartner prize of 

 one thousand florins, " The microscopical investigation of the 

 wood of living and fossil plants," the special object of the inves- 

 tigation being to ascertain characters whereby it would be 

 possible to determine the genus and species with certainty from 

 microscopical sections. Since then the literature of the subject 

 has enlarged somewhat, although the contributors have in 

 almost all cases confined their attention to the investigation of 

 special problems, rather than dealt with the subject as a whole. 

 Although the majority of these do not require citation at the 

 present time, one or two call for more special notice. 



An extended examination of the anatomical characters of the 

 stems of dicotyledons in general led Solereder, 3 in 1886, to the 

 conclusion that the characters to be met with are sufficiently 

 constant to admit of distinguishing families, tribes, genera, and 

 species. This is the most important generalization reached up 

 to the present time, and constitutes important evidence in 

 support of similar results more recently obtained. 



1 Die technischen Eigenschaften der Holzer, Stuttgart, 1860. 



2 Comp. Anat. Phan. and Ferns. 3 Bot. Zeit., XLIV, 506 (1886). 



