1 rr ( 



THE PRINCIPLES 



OF 



BIOLOGY. 



HERBERT SPENCEE, 



author of "social statics," "the principles of psychology. 



"essays: scientific, political, and speculative," 



"first principles," etc. 



VOL. II. 



NEW YORK: 

 D. APPLETON AND COMPANY, 



1, 3, and 5 BOND STREET. 



188 1. 



