The Leopard-frog or Meadow-frog, Rana pipiens {Schreber). 57 

 THE EGG-LAYING PROCESS. 



The meadow-frog may lay at any time of the day, even at noon (at 

 which time, April 27, 1911, we saw a pair leaving its mass), but more 

 frequently they spawn at night. They have a tendency to congregate in 

 large numbers and often 40 or more bunches of eggs are recorded within 

 small circumscribed areas. At such times, when an area is approached 

 the mated pairs often seek cover under the bunches which have already 

 been laid. From our first fragmentary observations, we concluded 

 that a pair did not remain in position more than 25 minutes for the 

 deposition of an egg-bunch, i. e., after the egg-laying had really begun. 

 Then, only the very end of the egg-laying had been observed. From 

 a captive pair taken May 4, 1907, the following notes were secured: 



3 fertilizations, 1§ minutes interval; 2 fertilizations, H minutes interval; 



4 fertilizations, 1^ minutes interval; etc. Several eggs were laid at an 

 emission. A stick was in the jar and it was between the hind legs of 

 the female. Neither she nor the male held anything. Doubtless this 

 was in part due to the cramped quarters, which made them take a semi- 

 vertical position. The male embraced with his hind limbs drawn up 

 on the back of the female. Evidently the mated pair keeps the on 

 position throughout egg deposition. Since this first observation, we 

 find that egg-laying may be completed in 5 minutes. When on a hori- 

 zontal branch the pair became very much flattened when spawning. 



THE EGGS. 



The egg-masses may be attached to submerged cat-tails (Plate i. Fig. 

 2f), twigs, sticks, grass, etc., or as often may rest on the bottom unat- 

 tached. Several times the water's surface has been so low (4 to 8 inches) 

 that the tops of the bunches appeared at the surface. They occur in the 

 open, unprotected, marshy expanses, or in overflows where the edges 

 and bottoms have plenty of grass. One will often find the egg-masses 

 interspersed with algse and dead leaves, which so fill the shallows that 

 the bottom can not be seen. In this species, as in the wood-frog, the 

 egg-masses may be clustered in special areas (Plate xv. Fig. 1). The 

 meadow-frog, however, tends to seek shallower water and more swampy 

 localities than the wood-frog. 



Some of the dangers to meadow-frog eggs are newts, rapid drying of 

 the shallows, and high-water currents. Many of the egg-masses are 

 laid in very shallow water and it does not require very much evapora- 

 tion to leave them high and dry. Sometimes this species lays in 

 back-waters or slow-moving streams. With high-waters or sudden 

 currents, the free masses of eggs, and some of the attached masses, are 

 carried some distance from the original site. In this process the masses 

 come to the surface; some separate into smaller ones, or even into the 

 single constituent eggs, which float free on the water's surface, some- 

 thing that occasionally happens with Rana clamata. 



