THE PRINCIPLES 

 OF BIOLOGY 



BY 



HERBERT SPEX(JER 



AUTHOK OF "social STATICS," " EBfCATION," " STUDY OF SOCIOLOGY," 



"essays: SCIENTIFIC, POLITICAL, AND SPECULATIVE," 



" FACTORS OF ORGANIC EVOLUTION," ETC. 



VOL. IT 



NEW YORK 

 D . A P P L E T O N AND C O M P A N i" 



189G 



