Professor in Columbia University

Revised. xii + 156 pages, 12mo$1.00

"The elementary part is clear and well calculated to introduce beginners to the study of the plants treated of. The excellent key makes the analysis of ferns comparatively easy. The writer cordially commends the book. It should be in the hands of all who are especially interested in the vascular cryptogams of the United States."—Bulletin of the Torrey Botanical Club, N. Y.

Henry Holt and Company

29 West 23d Street,New York

GEOLOGY

Vol I. "Geologic Processes and Their Results"

By Prof. THOMAS C. CHAMBERLIN

AND