jHf Jacob C. Cassel 



915 Arch Street, Philadelphia, Pa 



Manufacturer of 



AQUARIUMS 



Aquarium Ornaments 



Floral Terra Cotta, Etc. 



Goldfish Fish Globes Fish Food 



and all aquarium requisites. 



Send for Catalog. 



3QOO< )OOOC 



FRESH WATER BIOLOGY 



By HENRY B r WARD and GEORGE C. WHIPPLE 



WITH THE COLLABORATION OF 25 DISTINGUISHED SPECIALISTS 



All interested in aquatic biology will find here answers to their 

 queries on methods of study, conditions of existence, types of life, and 

 inter-relations of the organisms that inhabit our fresh-water bodies, 

 together with data on their life histories, habits and range. 



This work is the first complete and accurate record of North Amer- 

 ican aquatic life, especially the micro-organisms ; among both plants 

 and animals excluding the vertebrates, higher plants and bacteria, 

 every form is described that has been reported frorr a fresh-water body 

 on this continent. 



A comprehensive general discussion of each group precedes the 

 description of individual forms, which are arranged under a key to 

 permit of rapid and accurate determination of the genera and species. 

 Nearly every form is illustrated, and its diagnostic features are pointed 

 out. Biological* data on its habits, frequence and distribution are also 

 given. 



Fresh- Water Biology is a big book of 1111 pages, with 1547 illus- 

 trations. Price, $6.00, plus postage on four pounds. 



AQUATIC LIFE, 542 E. Girard Avenue, Philadelphia, Pa. 



"8 



50C3C 



3QOOC — IQOOC 



,c=o8 



i imr v- \ crr\ t t rmrt i > rmri( — -> 



Support 



The Government's War Activities 



Bui) W. S. S. 



h n 



3000000<=>OOOC 



Dao 8 



GEORGE A. SCHENK 



Mount Vernon, N. Y. 



-v-irw M-im-ir wiry >i — r 



.[ 



I L 



30 OOCZ3 



Cbe Mature ^tuDp Eetiieto 



OFFICIAL JOURNAL 

 AMERICAN NATURE-STUDY 

 SOCIETY 

 The numbers for the coming school year will 

 be filled with special articles from practical 

 teachers dealing with actual works, methods and 

 suggestions for school gardening, elementary 

 agriculture and nature-study. 



$1.00 per year. 15c. per copy. 

 Add for Canadian Postage 10 cents. 

 Foreign Postage. 20 cents. 

 With Aquatic Life, one year, $1.50. 

 ITHACA, N. Y. 



3ooo< — >oooooocr30oo' >Qoor— no 



