American Fisheries Society 291 



inches. The young frog requires only enough water to 

 allow him to jump in occasionally, as three-fourths of his 

 time is spent sitting in the grass or on the banks of the 

 pond. If the water is too deep in the pond the frog has 

 difficulty in getting in and out. 



The fact of the matter is that it is not absolutely necessary 

 for fully developed frogs to have any water at all. Once 

 for a period of sixty days one pond was entirely dry. At 

 this time it contained 15,000 frogs about three months old. 

 It was then I discovered a characteristic I had not known 

 of before. On going to the pond one morning I saw that 

 there was a great shortage of frogs. Seeing none dead I 

 was puzzled to know what had become of them. As I 

 was preparing to make a shipment I was alarmed and 

 began to investigate. On lifting up the overhanging grass 

 that borders the pond, I discovered in the clay banks 

 numerous small round holes an inch or inch and a half in 

 diameter, holes whicli I knew had not been there before. 

 Upon close examination I soon found that every hole 

 contained one or more frogs, which, upon taking some of 

 them out, I found to be sleek and moist as could be. The 

 following year I found the same condition, proving beyond 

 a doubt that frogs of this age are able to adjust themselves 

 to the absence of water. 



Ponds at the Crawford Station are constructed in the 

 following manner : The excavation is about 50 feet long, 

 25 feet wide and 20 inches deep. About 3 feet from the 

 edge of the pond on all sides a 12-incli board is set in the 

 ground about 6 inches deep. To this are attached uprights 

 about 3 feet in height. On top of these uprights a 6-inch 

 board is placed flatwise, the outer edge even with the up- 

 rights and the remainder projecting over the pond. To the 

 base board and top board is nailed 14-inch mesh galvanized 

 wire. This fence serves a twofold purpose. It not only 

 secures the frogs in the pond, but also excludes snakes, 

 which are great devourers of tadpoles and young frogs. 

 We construct our ponds for holding adult frogs in exactly 



