BIOLOGY 

 LIBRARY 



BIOLOGY LIBRARY 



First printed February 1890. Reprinted June 1890, Af<y 18)3. 



New and Enlarged Edition January 1896. Reprinted June 18 ,6, 



November \&ga,July 1900, Marc/t 1902, September 1903, /wJy 1905, 



Dtctmbtr 1907, January 1913, January 1915. 



ALL RIGHTS RESERVED 



