PREFACE. 
The first of the three papers which make up volume 14 of these 
Contributions is an extended work on the Lichens of Minnesota, by 
Prof. Bruce Fink, now of Miami University, Oxford, Ohio. This 
account is the result of several summers’ fieldwork in Minnesota, 
under the auspices of the Geological and Natural History Survey of 
that State, together with studies in his own laboratory and at the 
National Herbarium. The lichen flora of Minnesota is fairly repre- 
sentative of the lichen flora of a large portion of northern North 
America, from the Atlantic to the Pacific. This publication, there- 
fore, will be useful to students over a much wider area than that 
which it specifically covers. A series of the specimens enumerated 
in the catalogue of species is deposited in the United States National 
Herbarium, In the bibliographical work Prof, Fink was assisted by 
Mr. P. L. Ricker, of the United States Department of Agriculture. 
The bibliography of the works consulted in the preparation of the 
paper was prepared by Mr. Ricker. 
The second paper, by Mr. O. F. Cook, of the Department of Agri- 
culture, is a continuation of his study on the origin and distribution 
of the coconut palm, published in volume 7 of the Contributions. 
Much additional historical and botanical evidence is offered, tending 
to show even more conclusively than before that the coconut palm 
is a native of South America, and that it was carried westward across 
the Pacific in prehistoric times, instead of originating in the East 
Indies, as De Candolle and other botanical authorities have supposed. 
The remaining paper, by Mr. David Griffiths, of the Department 
of Agriculture, is a systematic account of the grasses of the genus 
Bouteloua and closely related genera, chiefly of the species found in 
North America. These are native grasses, some of them among the 
most important constituents of the natural pasturage of the West. 
Mr. Griffiths, in the 11 years since the beginning of his study, has had 
extensive opportunity for the observation of these grasses in the 
field, chiefly as engaged in the investigation of the public stock ranges 
for the Department of Agriculture; has examined the specimens in 
the United States National Herbarium and several other large herba- 
ria; and, for the study of the results obtained by others and the 
settlement of questions of nomenclature, has had at hand the excel- 
lent botanical resources of the Washington libraries. 
FREDERICK V. COVILLE, 
Curator of the United States National Herbarium. 
vV 
