BY
H. MARSHALL WARD, Sc.D., F.R.S.
FELLOW OF SIDNEY SUSSEX COLLEGE, HONORARY FELLOW OF CHRIST'S COLLEGE
AND PROFESSOR OF BOTANY IN THE UNIVERSITY OF CAMBRIDGE
PRESIDENT OF THE BRITISH MYCOLOGICAL SOCIETY, AND FELLOW OF THE
LINNEAN AND ROYAL HORTICULTURAL SOCIETIES; HONORARY FELLOW
OF THE MANCHESTER LITERARY AND PHILOSOPHICAL SOCIETY
AND OF THE BOTANICAL SOCIETY OF EDINBURGH
London
MACMILLAN AND CO., Limited
NEW YORK: THE MACMILLAN COMPANY
1901
All rights Reserved