INTRODUCTION 



TO 



STRUCTURAL AND SYSTEMATIC 



BOTANY, 



AND VEGETABLE PHYSIOLOGY, 



BEING 



A FIFTH AND REVISED EDITION 



OF 



THE BOTANICAL TEXT-BOOK, 



ILLUSTRATED WITH OVER THIRTEEN HUNDRED WOODCUTS. 



By ASA GRAY, M.D., 



USHER PROFESSOR OF NATURAL HISTORY IN HARVARD UNIVERSITY. 



IVISON, BLAKEMAN, TAYLOR & CO., 



NEW YORK AND CHICAGO. 



1877. 



