16 FROGS. 



rattlelike note of the wood frog, all three of which are frogs too small 

 to be considered commercially. 



In the shallow water, along the edges of swamps, or on the banks of 

 dead streams or backwaters one can find many leopard frogs. In the 

 early spring — in fact, at all times dm-ing the breeding period — they 

 can best be taken at night with an electric flashlight or acetylene lamp, 

 lantern, or jack of any kind. Later in the spring the frogs are more 

 easily captured dm-ing the day. To be sure that the captor has 

 individuals of both sexes, he must be able to distinguish them. The 

 male of a leopard frog has the thumb of the fore foot much enlarged 

 on the inner edge and has a vocal sac between each ear and shoulder. 

 These vocal sacs can be demonstrated by seizing the frog around 

 the waist just in front of the hind limbs and alternately squeezing and 

 relaxing the pressure. In this way a male will inflate the sacs. 

 The ripe females are very gravid and swollen and have no vocal 

 sacs and no enlarged thumbs. It seems advisable to have an equal, 

 or preferably greater, number of males than females to insure all the 

 females being mated. It seems to be the condition at the sexual 

 congresses of this species that the males exceed the females in num- 

 ber. Of course there is some evidence that a male may mate the 

 second time in a season, but this is not fully established. Frequently 

 the author has put his captives in close quarters to obtain quick 

 matings and then placed the pairs in the pond or inclosure meant 

 for the breeding purposes. To keep them mated more than two 

 or three days at the most in the laboratory or hatchery may result 

 in a long embrace, and this defeats the purpose of the operation. 

 If the culturist plans to begin with adult breeders, he can secure 

 individuals of this species without great difficulty, because it is so 

 gregarious at the time of the breeding assemblies; he will have a little 

 more difficulty in locating the smaller gregarious breeder, the pickerel 

 frog, and doubtless even a lesser measure of success in the case of the 

 more solitary green frogs and bullfrogs. 



It is yet a doubtful question whether the pickerel frog will become 

 as important a commercial form as the leopard frog, green frog, or 

 bullfrog. It is slightly smaller than the leopard fro^, and the acrid 

 secretion of its skin may militate against its availability. Whoever 

 wishes to experiment with it will not find it in exactly the same 

 habitat as the leopard frog. Tlie leopard frog is essentially a frog 

 (in its greatest abundance) of the cat-tail swamps, sedgy marshes 

 (PI. V, fig. 1), and grassy overflows (PL VII, fig. 1), while the pick- 

 erel frog is more often found in sphagnum bogs, marl ponds, 

 cold streams, in the shallows of mill ponds, or in the quiet waters 

 of bayous (PL V, fig. 2), away from the currents of our clear 

 streams. It usually appears from hibernation about the same time 

 as the toad and later than the leopard frog. When the air tempera- 

 tures approach 48 to 58°, pickerel frogs begin to appear and become 

 numerous at 58 to 67°. They hibernate in the water, and when it 

 reaches 45 to 53° they come out of their winter sleep. In point of 

 time this outcoming occurs between March 19 and April 25. The 

 croak of the male is low and grating, and usually to the tyro this 

 will be a poor guide for their capture. The male is usually smaller, 

 darker in color, and with the tnumbs enlarged, as in the males of 

 the leopard frog. 



