338 HAROLD CUMMINS 



Usually a male continued his efforts to clasp a female despite 

 her struggles, but frequently he desisted, even in a few instances 

 when her opposition was but weak. 



More instructive data were obtained from observations in 

 terraria. Some of them are presented below; with the exception 

 of nos. 5 and 10, each observation or experiment was repeated, 

 with results no different from the cited cases. 



Observations in terraria 



1. Wood frog, April 1st. The frogs of a pair were separated and 

 placed in a large glass container with 1| inches of water. The male 

 swam first in one direction and then in another, with no relation to the 

 position of the female and without touching her. After a short time 

 he stopped about 2 inches behind and to the right of the female. 

 Then with a sudden jump he mounted, encountering no resistance. 

 After being again separated, the male swam about as before. The 

 female alternately crouched at the bottom of the dish and swam 

 erratically. Activities of this nature followed for twenty minutes, 

 when the frogs encountered each other snout to snout. Suddenly the 

 male clasped the female about her head and then gradually worked 

 backward until he secured a hold in front of her fore legs. After two 

 minutes a sudden maneuvre placed the male in the correct position 

 for a pectoral clasp. During this procedure neither frog croaked and 

 the female did not resist. 



2. Wood frog, April 1st. A male and a female which had not been 

 clasping were placed in a container with leaves but no water at the 

 bottom. With his fore legs touching her, the male crouched at the 

 side of the female. Suddenly he jumped upon her and attempted to 

 clasp, at the same time squawking loudly. But the female resisted, 

 jmnping up on her hind legs and turning the ventral surface upward. 

 She succeeded in dislodging the male and he did not again try to 

 clasp her. This clasping and dislodgment occupied not more than a 

 half minute. 



3. Wood frog, April 1st. A number of individuals of both sexes 

 were confined in a terrarium. A male secured a clasp upon another 

 male. The clasped male resisted, croaking and turning on his back. 

 After a few seconds the clasping male loosed his hold. 



4. Wood frog, April 2nd. Three males which had been clasping 

 were placed in a terrariiun with a male so disabled that he could not 

 use the hind legs. After a few minutes the disabled male was clasped, 

 and was held so for several hours. 



5. Wood frog and leopard frog, April 1st. Two male wood frogs 

 were confined in a terrarium with about twenty leopard frogs of l)oth 

 sexes. On the morning of April 1st, after two days in the terrarium, 

 one of the wood frogs clasped a female leopard frog. He experienced 



