The American Toad, Bufo lentiginosus americanus LeConte. 31 



When spawning has begun or the female is almost at the ovulation 

 process, it seems a difficult matter to arrest ovulation. On April 5, 

 1910, four pairs were captured, three of which were beginning laying 

 and the fourth had not started. In the first jar we placed a female 

 in water but isolated the male. The female finished her complement. 

 In the second jar the pair were left in water and they completed ovula- 

 tion. In the third case the pair were placed in a dry jar, but they laid 

 their eggs. The fourth pair, which had not begun when captured, laid 

 in a dry jar. In all cases, a male was present at the inception of spawn- 

 ing or during its entire process. We have one record (May 3, 1907) of 

 a female laying with no male present. We tried only once to see if 

 females would lay when placed with males of other species. A pair 

 of mated toads and a pair of pickerel-frogs were taken. The males 

 were taken off and transposed. The following morning the female toad 

 had laid, but we have no certain evidence that the male pickerel-frog 

 mated with her during the night. 



THE EGG-LAYING PROCESS. 



Egg-laying takes place both by day and by night. It has been 

 noticed frequently, but the process was observed most minutely April 

 30, 1907, in a pond where hundreds of pairs were laying on introduced 

 Marsilea. The male always seeks to get his vent as near that of the 

 female as possible. Usually the male puts his hind legs, or his feet 

 at least, between the hind limbs of the female. Great variations in 

 this particular are observed. Rarely the outer metatarsal tubercle rests 

 on the dorsum of the thigh of the female. Occasionally, instead of 

 putting his legs between those of the female, a small male (though not 

 exclusively so) draws his legs up after the usual fashion, except that 

 they rest on the back of the female around her vent. In one case the 

 soles of the male's hind feet were obliquely perpendicular and facing 

 backward. Again, another male locked his hind legs under and at right 

 angles to the thighs of the female. The females, at the beginning of 

 fertilization, straighten their more or less bowed legs, which in turn 

 hold the hind feet of the male. Each period of sperm- and egg-emission 

 consumes about 5 seconds. Within this time a male makes from 4 to 

 12 emissions of sperm. At such a period, from each oviduct a string 

 of eggs 2 to 7 inches long may be voided by a female at one effort. After 

 this period of activity the male remains in the fertilization attitude 

 from 1 to 3 minutes, i. e., with his hind feet between those of the female. 

 Instances have been recorded where they so remained 9 or 10 minutes. 

 Often, however, when bothered by another male immediately after 

 emission, he uses his hind legs to ward off the intruder. 



Quite frequently the eggs after emission remain for some time about 

 the vent. In some instances, the male holds them up temporarily by 

 his hind feet, which are brought up under the vent of the female. In 



