The Recognition of Sex 233 



Males, Goltz concluded, are not drawn toward the 

 females through one sense alone, but by means of 

 several senses, no one of which is indispensable. It 

 is a striking fact that a frog whose head is cut in 

 two so as to remove the cerebral hemispheres and 

 eyes will nevertheless continue to clasp a female that 

 is presented to him, while he soon rejects one of 

 his own sex. 



The bodies of females are commonly plumper 

 than those of the males. May the latter perchance 

 distinguish the females by their form? Goltz tried 

 the experiment of stuffing out the body of a male 

 frog and giving it to another male, but he found 

 that it was soon abandoned. Does the male frog 

 have so delicate a tactile sense that even though 

 nearly brainless he cannot be deceived as to which 

 sex is within his grasp? Goltz is inclined to con- 

 sider that such is the case. It may be open to doubt, 

 however, if the possibility was sufficiently consid- 

 ered that sex recognition may be a result of the 

 behavior of the two sexes, much as it was found to 

 be in amphipods. Despite the interesting experi- 

 ments of Goltz the matter requires further investi- 

 gation before a decided conclusion can safely be 

 drawn. 



In the birds the sexes may often be easily dis- 

 tinguished by sight, and in many species each sex is 

 doubtless able to recognize the other by this sense 

 alone. The discrimination may be aided by the ob- 

 servation of differences in behavior. There is little 



