The Recognition of Sex 227 



if they were members of the other sex. In one case 

 a mutilated male was carried about for over five 

 hours. The mutilated males were more active than 

 females are under the same conditions, and did not 

 assume the same bodily attitude, but nevertheless 

 their captors carried them without any manifest 

 awareness of the deception to which they were sub- 

 jected." 



In another group of crustaceans, the Copepoda, 

 the mating instincts are more or less analogous to 

 those of the amphipods. In the copepods, however, 

 the males in seizing the females employ the first an- 

 tennae, which are often enlarged and especially mod- 

 ified for this function. In Cyclops fimbriatus, whose 

 behavior was studied by the writer, the male clasps 

 the female just in front of an enlargement at the 

 base of the abdomen. Males show much eagerness 

 in grasping the females, and they may be poked 

 about roughly with a needle and the posterior part 

 of the body may be cut off without causing them to 

 leave their hold. 



"As the pairs of Cyclops 1 swim through the water 

 the males are usually the more active. Frequently 

 the female remains entirely quiet with the appen- 

 dages drawn close to the body, and the body flexed 

 ventrally, allowing herself to be passively carried 

 about by her mate. At other times the female may 

 swim as actively as the male. In general the be- 



1 Quoted from Holmes on "Sex Recognition in Cyclops," Bio- 

 logical Bulletin, Vol. 16, p. 313, 1909. 



