FEOG CULTUEE 225 



a strip of muslin at least six inches wide, pro- 

 jecting horizontally inward, so that frogs 

 which succeed in climbing to the top cannot go 

 any further. A frog can climb almost any- 

 thing vertical, short of a smoothly planed board, 

 and in trying to escape will display astonish- 

 ing perseverance. Specimens have been seen 

 clambering laboriously to a horizontal board 

 and dropping invariably to the ground after 

 reaching the top, only to repeat the effort again 

 and again for hours at a time. 



Ponds designed to hold frogs or tadpoles 

 through the winter season must have soft 

 muddy bottoms into which they can burrow and 

 hibernate. It is also desirable that the banks 

 of all ponds for fully developed frogs have 

 sloping sides, so that the creatures can easily 

 be screened to prevent their escape. 



The average depth of the smaller ponds may 

 be only a foot and a half or two feet ; or a little 

 more than the thickness of the heaviest ice 

 likely to form in winter. A kettle is not as 

 necessary as in a pond built for propagating 

 warm-water fishes, yet it would probably be 

 beneficial. A large pond for the adults may be 



