SCIENTIFIC PAPERS. 



A STUDY OF THE VENATION OF THE SPECIES OF SALIX 

 DESCRIBED IN GRAY'S MANUAL, WITH REFERENCE TO THEIR 

 DETERMINATION. 



BY N. M. GLATFELTER, M. D. 



Introduction. 



am 



fore, at distinguishing the species of Salix by their veining 

 alone. That the accomplishment of this object is desirable 

 will readily be granted. We distinguish the faces of in- 

 dividuals, or family characteristics, without being able, 

 easily, to point out the particulars causing the different 



impressions. An 



elm 



from another, by its form as produced by the special mode, 

 in each case, of the distribution of the branches. It is be- 

 lieved that a careful study of the venation of willows will 

 be a means, at least equally decisive in arriving at results; 

 for the differences in their venation, though on a smaller 

 scale, are, I think, equally striking. Should the following 

 descriptions not always be sufficiently clear and definite, 

 there will still remain the impression produced in each 

 particular case, upon the force of which I would insist. 



A glance at the accompanying plates will show the wide 

 variety of venation. That no difficulties present them- 

 selves, by this method, is not claimed. At two or three 

 points where certain species approach each other with ex- 

 treme closeness, the determination dependent wholly upon 

 the method, might, in single instances, fail, even in the 

 hands of an expert. For, besides this similarity between 



certain 



in the 



Reprints issued Oct. 5, 1893. 



