FROGS. 15 



usually be undesirable; they might lay in transit, break the embrace 

 en route, or never lay at all, as is generally the rule. A more ex- 

 tended discussion of the five or six groups of stock follows: (1) Indi- 

 vidual frogs; (2) mated pairs; (3) eggs; (4) tadpoles; and (5) 

 transition stages. 



INDIVIDUAL PROGS. 



In many ways it might appear that the easiest and most certain 

 method of securing stock would be to begin with the individual frogs. 

 To be sure, they are to be found throughout the active period of the 

 year — that is, irom the early thaws of spring to the hard frosts of 

 fall — ^but one must know their breeding season or he may carry them 

 almost a year before the first eggs are secured. If the material come 

 from a supply bureau, there is no certainty as to the period of previ- 

 ous captivity, the amount of freedom the frogs had in such quarters, 

 etc. Frequently it has been found that with the leopard frog, green 

 frog, and bullfrog the males were first captured and the females taken 

 later, sometimes two or three weeks afterwards. To hold the males 

 in captivity or in close quarters tends to reduce their breeding 

 potentiality. Or, if females be captured just before breeding and be 

 brought into the hatchery to await the subsequent capture of im- 

 pulsive breeding males, tlie chances are that in rare cases the female 

 may lay without the male, or that, by the time a pair or pairs are 

 mated in the laboratory or hatchery, one or the other member may 

 be weakened, and the pair may continue in the embrace several 

 weeks until the death of one or both individuals. In most cases such 

 a mated pair proVes unfruitful. Over and over again has the writer 

 taken gravid females and mated them with captive males or with 

 Jnales subsequently taken, and in almost every instance no eggs were 

 laid or, if so, they were frequently infertile. 



If, however, the experimenter has a good pond or water inclosure, 

 with more or less natural conditions, he might stock it with indi- 

 vidual frogs and not encounter the above difficulties so inherent in 

 confining frogs in close quarters. If the prospective culturist wishes 

 to start with the individual frogs, he must choose or determine what 

 species he prefers or what his region offers. At present the four 

 principal eastern species for the frog market are the leopard frog, the 

 pickerel frog, the green frog, and the bullfrog. 



If the leopard frog be chosen, the person who purposes to breed 

 this species can usually secure enough frogs from the swampy marsh- 

 lands (PI. V, fig. 1), or backwaters and overflow ponds of streams 

 in his own neighborhood. The leopard or spring frog appears from 

 its hibernation in the muddy bottoms of our marshes and ponds 

 when the streams have just freed themselves of ice and the lowlands 

 are overflowing. When the temperature of the water reaches 41 

 to 50°, they may confidently be expected to appear in num- 

 bers.'* From the middle of March to the middle of April is the 

 period in which to expect them to appear for breeding. In early 

 spring, whenever a low guttural croaking is heard in swampy 

 stretches, it is that of the leopard frog. The croak is wholly unlike 

 the shrill notes of the peeper and swamp cricket frog or the short 



a The dates of first appearance, spawning, etc., of the commercial species were determined tor the lati- 

 tude of Ithaca, N. Y., but might well apply for northeastern United States if not for all cinortbein Onited 

 States. 



