ON THE PEEPING FROG. 315 



gradually dense with this ear-deafening, all-pervading sound ; occasionally the voices fall 

 into a regular measure of time, but the effect is usually a medley of shrill sounds, a few 

 voices audible above the others by reason of some peculiarity in key, or lack of smoothness 

 in utterance. The piping of each individual is long continued ; the interval between these 

 musical efforts appears to depend on the mood of the musician. One does not note the 

 pause of individual voices in the general effect, but, however loud and earnest the piping 

 may be, the introduction of any unusual sound or appearance, even the low quick flight of 

 a bird over the water, is almost sure to give alarm and still them for a while ; the frogs 

 along the edge of the shore commonly settling away out of sight for safety among the dead 

 leaves under water, while those having a position on the low bushes or reeds merely cling 

 more closely, flattening the body against the object on which they are resting. The inter- 

 val of silence is brief; soon a frog rises and gives a shrill " peep," which is immediately 

 answered by dozens of voices. The sounds may appear to come from about your feet, but 

 for the reasons given, the chances are against sesing the frogs till some movement in the 

 water as they rise from their hiding places, arrests the eye, which on perceiving one usu- 

 ally discovers more. 



Among the enemies that prey on Pickeringii none are more destructive while they are 

 collected at the water than R. halecina, the shad frog ; both species congregating for egg- 

 laying in the same localities. On one occasion numbers of both frogs had assembled in a 

 small, shallow pool ; the peeping frogs were in commotion, swimming about and by turns 

 climbing any available grass or weed stalk to avoid- the near approach of halecina. Sud- 

 denly a gust of wind swept a shower of dead leaves that had remained on the tree all win- 

 ter, from an oak standing near, and scattered them over the water. No sooner were these 

 graceful rafts afloat than Pickeringii appropriated them as points of safety, nearly all of 

 them becoming freighted with a little frog. Hither and thither with the eddying breeze 

 they sailed while halecina swam under and about them, the curled and upturned edges of 

 the leaves concealing the little frogs from sight. 



Where Pickeringii is numerous, a handful of dead grasses and leaves taken at random 

 from the shallow water alone; the shore will usually be found to contain a few esrars 

 attached singly here and there. Mr. F. W. Putnam, in the Proc. of Boston Society Nat- 

 ural History, vol. ix, p. 229, has already described them as follows : " These eggs were 

 not in a mass or in a string, as is the case with our other frogs and toads, but were isolated, 

 being attached to the plants some distance apart. The tadpoles were hatched in about 

 twelve days, and were very long, coming from the eggs with a more marked tadpole form 

 than is the case with our other species of frogs and toads." To this description I would 

 add that of the color of the egg, which is at first deep brown on the upper surface and 

 cream colored beneath, but in the process of development changes to drab; and the tadpole 

 escapes from the outer membranous shell of a pale yellow color with dots of deep brown 

 on the sides of head and body, and measures about 5 mm. in length (pi. 28, fig 1). The 

 eggs are so small that they might easily pass for scattered seeds of the submerged weeds to 

 which they cling tenaciously by means of the viscid substance surrounding them. 



The length of time occupied in the development of the egg varies according to circum- 

 stances ; in the early part of the season they ordinarily hatch, as Mr. Putnam has observed, 

 in twelve days ; as the weather grows warmer I have known it accomplished in seven. In- 



