A COURSE 



or 



PRACTICAL INSTRUCTION 



IN 



ELEMENTARY BIOLOGY 



BY 



T. H. HUXLEY, LL.D., SEC. R.S., 



ASSISTED BY 



H. N. MARTIN, B.A., M.B., D.Sc., 



PROFESSOR OF BIOLOGY IN JOHNS HOPKINS UNIVERSITY, BALTIMORE; 



FELLOW OF CHRIST'S COLLEGE, CAMBRIDGE, AND OF 

 UNIVERSITY COLLEGE, LONDON. 



, THIRD EDITION, REVISED. 

 *" 



THE 



NIVERSITY 



MACMILLAN AND CO 

 1877. 



