





BIOLOGY 



LIBRARY 



G 



(Eamtmlige : 



PRINTED BY J. AND C. F. CLAY, 

 AT THE UNIVERSITY PRESS. 



First Edition 1876. Second Edition 1877. 

 Third Edition 1879. Fourth Edition 1883. 

 Reprinted 1884, 1886. Fifth Edition 1889. 

 Reprinted 1891. Sixth Edition 1895. 



