ANIMAL LIFE 



FIG. 353. Spider crab often found covered with seaweeds and hydroids so as to 

 appear like a stone or stick. Photograph by Overton. One third natural size. 



FlG. 354. Tree frog. A, after assuming a protective color ; B, before assuming 

 the dark protective color of the bark which it took on fifteen minutes later. 



Photograph nearly half life size. 



