ADVANCED TEXT-BOOK 
OF 
LIOOLOG ¥ 
FOR THE USE OF SCHOOLS 
BY 
HENRY ALLEYNE NICHOLSON 
M.D., D.Sc., M.A., Px.D. (GérT.), F.R.S.E., F.G.S. 
PROFESSOR OF NATURAL HISTORY AND BOTANY IN UNIVERSITY COLLEGE, TORONTO ; 
FORMERLY LECTURER ON NATURAL HISTORY IN THE MEDICAL SCHOOL 
OF EDINBURGH ; ETC. ETC. 
SECOND EDITION 
REVISED AND ENLARGED 
WILLIAM BLACKWOOD AND SONS 
EDINBURGH AND LONDON 
MDCCCLXXIII 
The Right of Translation is reserved 
