The Wood-frog, Rana sylvatica LeConie. 93 



had 16 bunches attached to it. In 1910, in still another locahty, 22 

 bunches were recorded in one small area. 



We have found that to capture mated pairs it is best to watch the 

 area about the first bunch of eggs deposited in a pond. Most of the 

 numerous pairs taken were thus secured. They are often under cover 

 near the egg-area or at times directlj^ beneath the masses. Our best 

 record of captures may serve to show how fruitful such search can be. 

 On April 6, 1908, under and above the sedge area which two days later 

 had 37 bunches, six pairs of mated frogs were captured. 



The time consumed in the laying is quite short. On April 27, 1906, 

 a gravid female was taken and at ll'^SO'" a. m. was placed with two 

 males. By 1'^ 30" p. m. it was mated. At 2^ 30"", when I left the labor- 

 ator}', there were no eggs. At 3 o'clock, upon return, a whole bunch 

 was found, thus taking 30 minutes or less in the laj^ing. Since this 

 record (our first evidence) we have found that 5 to 10 minutes suffice for 

 the process. 



Of the egg-laying position and process, we have three observations. 

 At 7''35'" a. m., March 28, 1907, I found a horizontal tuft of grass with 

 a bunch of wood-frog's eggs. Upon closer examination a mated pair 

 was discovered near the attachment of the blade, evidentlj'' in the 

 egg-laying act. After a minute or so, they became uneasy and sud- 

 denly attempted to escape. The blade was perfectly horizontal and the 

 female was resting on it, not holding it. The bunch the.y laid was the 

 second on the stem. At 7'' 45"' I left and returned again at 10'' 30"' a. m. 

 When about to take this second bunch, another mated pair was de- 

 tected directly beneath the blade. On the following day, in another 

 pond, another favorite position was noticed. A mated pair was lying 

 on top of the bunches of one of the egg-areas already described, and from 

 the restless movements of their legs they were evidently ready to begin 

 laying; this process is not rapid at first. Probably, as with some of the 

 other frogs, a few eggs may be extruded and then a short interval may 

 pass before the rapid ovulation of the bulk of the complement comes. 

 For example, on April 6, 1908, when a rapid rush was made on an area 

 containing 17 bunches, it was observed that a mated pair had been 

 frightened from the top of the egg-area. About the vent of the mated 

 female were 15 fresh eggs, the beginning of ovulation to which reference 

 has already been made. 



We have long suspected that the female R. sylvatica, as with other 

 species of Rana, might lay without attendant males. At 8'' 45"' p. m., 

 March 30, 1910, a female was captured near the edge of a pond. It 

 was on its way to the water. In the laboratory it was placed with a 

 spent female. Three days later it laid a whole complement, with no 

 males near it, much less mating with it. Evidently, when captured, 

 the female was on the eve of laying, as we believe is true of all the females 

 of this species the minute they reach the ponds. 



