By Alfred C. Stokes. 



I. 

 AQUATIC MICROSCOPY 



FOR BEGINNERS. 



Price, postpaid, $1.50. 



II. 



FRESH-WATER ALGtE AND THE DES- 

 MIDIEM, 



Price, Postpaid, $1.25. 

 III. 



MICROSCOPICAL PRAXIS. 



Price, Postpaid, $1.50. 

 Address E. F. Bigelow, Portland, Conn. 



