The Pickerel Frog 



palpitating white throats also in crannies at the mouths of surface 

 drains. 



The eggs of this species are laid in shallow water during the 

 month of May. Frogs brought from the pond laid eggs on the 

 nights of May i8, 23, and 26, 1902. The irregular egg 

 masses are about two inches in diameter, and contain between 

 two and three thousand eggs each. The upper half of the egg 

 is rich brown in colour; the lower half cream-white. The eggs 

 are small (ij mm.) and enveloped in triple spheres of transparent 

 jelly. The earlier stages of the development take place very 

 rapidly. The jelly holds its compact shape but a very short 

 time; it softens, and the whole mass spreads and flattens. The 

 tadpoles, which are light yellowish-brown in colour, leave the 

 eggs very early. Eggs laid May 23rd were hatched May 27th. 

 The tadpoles cling to the jelly side by side in rows and circles, 

 with their heads up and their tails extending downward. The 

 next day they are festooning the waterweeds as well as the jelly. 

 Now they begin those circling tours, from which they settle to some 

 new support, only to start off again in large circles, which give 

 place to smaller ones until they fmd another support or drop 

 lightly to the bottom. By the first week in June, the gills have 

 become wholly covered, and the bits of life have grown to ordinary 

 round-bodied " pollywogs," with the usual pollywog hunger.^ 

 From now on they vary greatly in size, some far outstripping 

 the others, although all live under the same conditions. The 

 larger ones change to the frog form in July and August; the 

 smaller ones may be kept back in the process until September; 

 and still others may delay the change until the following spring. 



Large tadpoles of the Pickerel Frog have at first sight much 

 the appearance of the Green Frog tadpoles. Looking more 

 closely, we see that the head is much more pointed, the eyes are 

 not widely separated, and the nostrils are close to the end of the 

 muzzle, characteristics which distinguish this species. The 

 younger tadpoles have small roundish spots irregularly placed 

 on a greenish-brown background of body and tail. The dark 

 pigment follows the lines between the muscle-plates of the tail 

 so that for nearly one half its length the tail looks like a black 

 feather. The tail fin is less than one-fourth of an inch wide 



1 The mouth structure of the pickerel frog tadpole is similar to that of the bullfrog tadpole. 

 (See footnote, p 235.) 



191 



