340 HAROLD CUMMINS 



time the pairs were separated and the frogs returned to the terrarium. 

 At 1 :45 p. M. only one of the females was clasped. 



13. Leopard frog, March 30th. Several individuals of both sexes 

 were placed in a terrarium. When touched by a female one of the 

 males croaked forcibly. The terrarium was crowded and the female 

 was climbing over him. 



14. Leopard frog , March 30th. When rubbed or touched, even Hghtly, 

 by other males (in the same terrarium as no. 13) the response was the 

 same as when a female touched a male. 



15. Wood frog, April 1st. A clasping pair of wood frogs, three males, 

 and two females were placed in a terrarium. A single male approached 

 the pair, and when he touched them the clasping male croaked and 

 warded off the intruder with his hind legs. The approaching male 

 made no effort to clasp. 



From the foregoing observations, it is evident that males 

 attempt to clasp individuals of both sexes under experimental con- 

 ditions as well as in the pond. In no. 1 the female did not 

 resist and the male retained his clasp. On the other hand, in 

 no. 9 she resisted strenuously, but the male succeeded in clasp- 

 ing and remained in spite of the resistance. In no. 2 and no. 8 

 the females dislodged the males. Thus there seemed to be no 

 consistent reaction of clasped females. When males were 

 touched by other frogs (nos. 13, 14 and 15) they croaked, and 

 this alone seemed to be at times sufficient to frustrate further 

 attempts of the approaching males. But sometimes, as in no. 3 

 both resistance and vocal remonstrance followed an actual 

 attempt to clasp. In no. 4 the clasped male was unable to offer 

 resistance, and the clasp in this case was retained for several 

 hours. In agreement with Banta, there was no consistent 

 difference in the resistance offered by the two sexes, except that 

 males, unless experimentally disabled, always croaked or resisted, 

 or did both, ^vhile females sometimes resisted and sometimes 

 failed to do so. Neither was there a consistent ardor of the at- 

 tacking males; sometimes, in spite of resistance offered by a fe- 

 male, he struggled until a hold was established; at other times 

 the males. were not persistent in their attempts upon females. 

 But attempts on males were not continued. Pairing did not 

 occur in all cases when frogs were placed in terraria, as in no. 11. 

 It is significant that on the two days preceding this experiment 



