Denies Scientific *Pr inters 

 Edited by J.^ynolds Green&fD., F.R.S. 



BIOLOGY 



BY 



R. J. HARVEY GIBSON, M.A. 



Professor of Botany in the University of Liverpool 



WITH 



NUMEROUS 



ILLUSTRATIONS 



London: /. 5I/. 



& JO Bedford Street, W.C 



