LIST OF ILLUSTRATIONS. 
FIG. 
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Note. — The figures in brackets [il following the titles re¬ 
fer to the list, printed below, of books from which the 
illustrations are, by permission, respectively borrowed. 
An Insect-net. 
The House-cricket [1]. 
A Cabbage-butterfly. 
Spider and Web. 
A Water-snail. 
Shell of a Fresh-water Mussel [2]. 
An American Pondweed. 
The Hornwort. 
A Duckweed. 
Other Pond weeds.. 
The Hydra [ 2 ] . 
Water-fleas and Cyclops. 
Caddis-fly Cases (2]. 
The Larva of Dragon-fly. 
Larva of Dyticus. 
Larva of Whirligig Beetle. 
Larva of a May-fly. 
Side View of Crayfish [5]. 
A Campanularian Hydroid Colony [6]. 
A Sertularian Colony [6]. 
A Net for Collecting at the Seaside. 
Sea-anemones. 
A Starfish [6]. 
A Sea-urchin. 
A Sea-cucumber. 
A Hermit-crab. 
A Shrimp. 
Tumbler with Chloroform. 
A Cockroach [1]. 
Mourning-cloak Butterfly. 
A Wasp’s Nest [3]. 
Cocoon of Cecropia. 
Eggs of Frog Just Laid [2]. 
Eggs of Frog a Few Hours After Laying [2]. 
Apparatus for Decomposing Water.. 
Apparatus for Removing Oxygen from Air. 
Heating a Test-tube.. 
The Parts of a Locust .. 
Comparison of a Grasshopper and Man..... 
xvii 
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