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 Achetidse ; 
but he failed to find any rudiments in the females 
of Decticus, one of the Locustidse. 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. 
