GEORGE ENGELMANN. 445 
up to the time. Nothing of importance is yet to be added to 
what he modestly styles “Notes on the Genus Yucca,” pub- 
lished in the third volume of the Transactions of the St. Louis 
Academy, 1873, and not much to the “ Notes on Agave,” 
illustrated by photographs, included in the same volume and 
published in 1875. 
Less difficult as respects the material to work upon, but 
well adapted for his painstaking, precise, and thorough hand- 
ling, were such genera as Juncus (elaborately monographed 
in the second volume of the Transactions of the St. Louis 
Academy, and also exemplified in distributed sets of speci- 
mens), Euphorbia (in the fourth volume of the Pacific Rail- 
road Reports, and in the Botany of the Mexican Boundary), 
Sagittaria and its allies, Callitriche, Isoetes (of which his 
final revision is probably ready for publication), and the 
North American Loranthacee, to which Sparganium, certain 
groups of Gentiana, and some other genera, would have to 
be added in any complete enumeration. Revisions of these 
genera were also kindly contributed to Dr. Gray’s Manual ; 
and he was an important collaborator in several of the memoirs 
of his surviving associate and friend. 
Of the highest interest, and among the best specimens of 
Dr. Engelmann’s botanical work, are his various papers upon 
the American Oaks and the Conifer, published in the 
‘Transactions of the St. Louis Academy,” and elsewhere, the 
results of long-continued and most ,conscientious study. The 
same must be said of his persevering study of the North Amer- 
ican Vines, of which he at length recognized and characterized 
a dozen species, — excellent subjects for his nice discrimina- 
tion, and now becoming of no small importance to grape- 
growers, both in this country and in Europe. Nearly all that 
we know scientifically of our species and forms of Vitis is 
directly due to Dr. Engelmann’s investigations. His first 
separate publication upon them, “The Grape Vines of Mis- 
souri,” was published in 1860; his last, a reélaboration of 
the American species, with figures of their seeds, is in the 
third edition of the Bushberg Catalogue, published only a few 
months ago. 
