lateral folds. When caught in the breeding pools, the body seems 

 broad and flat and rather soft, and dark in color, but when caught 

 later in the woods, the form is compact, more slender, and the frog 

 has a very alert appearance. Some individuals have inky dashes on 

 the sides and occasionally on the back. 



Structure: Head pointed; legs long; webs of hind feet of males 

 very convex at breeding season; hind leg long (.^-.62 in length of 

 body while .61-. 74. in R. cantabrigensis). 



Voice: The wood-frog's note is very short, a sharp snappy clack. 

 At times 2, 4, or 6 notes are given in rapid succession; and when close 

 at hand, they sound high and grating in character. It can be heard 

 only a short distance from the pond. In chorus, it is more of a rattle 

 than with any other frogs. It has often been likened to the ''quacking" 

 of ducks. 



Breeding: They breed from March 19 to April 30, at a temperature 

 of about 50 F. The egg mass is globose, 2 1/2-4 inches (62-100 mm.) 

 in diameter, the individual eggs appearing larger than in R. pipiens, 

 freer and the outer envelope of each egg keeping its spherical form. 

 The egg is 1/14-1/10 inch (1.8-2.4 mm.), the inner envelope faint, 

 1/7-1/4 inch (3.6-5.8 mm.), the outer, distinct 1/5-2/5 inch (5.2- 

 9.4 mm.). The egg complement is 2,000-3,000. The deep olive tad- 

 pole is medium, 2 inches (49.8 mm.), its tail long with tip acuminate 

 and dorsal crest very high. The tooth ridges are 3/4. After a tadpole 

 period of 44 to 85 days, they transform from June 8 to August 1, 

 mostly before July 15 at 5/8-3/4 inch (16-18 mm.). 



Notes: April 6, 1908. Southeast Slaughter House Pond, Ithaca, 

 N. Y. As I approached the pond, I heard the greatest chorus of low 

 grating croaks I ever recorded from wood-frogs. This was at 1 1 130 

 a. m. From the south I crawled upon them (bellywise using elbows to 

 move along slowly). At times, I used my opera glasses. In this way, 

 I was able to reach the edge of pond without disturbing croakers. In 

 this pond were at least 200 males croaking. . . . Where yesterday there 

 was only one Rana sylvatica bunch, there were now 17 bunches of 

 eggs laid April ^-6. When I arose they all disappeared simultaneously. 

 To go through the pond one would little realize 200 males were there, 

 to say nothing of the females. 



Since many of the egg masses are laid near the edges of shallow 

 ponds, many egg masses are left high and dry. A far more serious 

 source of danger is freezing. Most of the bunches are laid from 1/2-2 

 inches beneath the water's surface. In many instances, long before the 

 hatching period approaches, the tops of these complements appear at 

 the surface because of the reduction of water level by rapid evap- 

 oration. 



