Chap. X. ORTHOPTERA. 359 



be compared with that of the reindeer, in which species 

 alone both sexes possess horns. Although the female 

 orthoptera are thus almost invariably mute, yet Landois 41 

 found rudiments of the stridulating organs on the fe- 

 mora of the female Acridiidae, and similar rudiments on the 

 under surface of the wing-covers of the female Achetidae ; 

 but he failed to find any rudiments in the females 

 of Decticus, one of the Locustidae. In the Homoptera 

 the mute females of Cicada, have the proper musical 

 apparatus in an undeveloped state ; and we shall here- 

 after meet in other divisions of the animal kingdom with 

 innumerable instances of structures proper to the male 

 being present in a rudimentary condition in the female. 

 Such cases appear at first sight to indicate that both 

 sexes were primordially constructed in the same manner, 

 but that certain organs were subsequently lost by the 

 females. It is, however, a more probable view, as pre- 

 viously explained, that the organs in question were 

 acquired by the males and partially transferred to the 

 females. 



Landois has observed another interesting fact, namely 

 that in the females of the Acridiidae, the stridulating 

 teeth on the femora remain throughout life in the same 

 condition in which they first appear in both sexes 

 during the larval state. In the males, on the other 

 hand, they become fully developed and acquire their 

 perfect structure at the last moult, when the insect is 

 mature and ready to breed. 



From the facts now given, we see that the means 

 by which the males produce their sounds are extremely 

 diversified in the Orthoptera, and .are altogether dif- 

 ferent from those employed by the Homoptera. But 

 throughout the animal kingdom we incessantly find the 



41 Landois, ibid. s. 115, 116, 120, 122. 



