286 THE DESCENT OP MAN. 



Landois has observed another important fact, namely, that In 

 the females of the Acridiidse, the stridulating teeth on the femora 

 remain throughout life in the same condition in which they first 

 appear during the larval state in both sexes. In the males, on 

 the other hand, they become further developed, and acquire their 

 perfect structure at the last moult, when the insect is mature and 

 ready to breed. 



Prom the facts now given, we see that the means by which 

 the males of the Orthoptera produce their sounds are extremely 

 diversified, and are altogether different from those employed by 

 the Homoptera.*^ But throughout the animal kingdom we often 

 find the same object gained by the most diversified means; this 

 seems due to the whole organization having undergone multifari- 

 ous changes in the course of ages, and as part after part varied 

 different variations were taken advantage of for the same general 

 purpose. The diversity of means for producing sound in the three 

 families of the Orthoptera and in the Homoptera, impresses the 

 mind with the high Importance of these structures to the males, 

 for the sake of calling or alluring the females. We need feel 

 no surprise at the amount of modification which the Orthoptera 

 have undergone in this respect, as we now know, from Dr. Scud- 

 der's remarkable discovery," that there has been more than ample 

 time. This naturalist has lately found a fossil insect in the 

 Devonian formation of New Brunswick, which is furnished with 

 "the well-known tympanum or stridulating apparatus of the male 

 "Locustidae." The insect, though in most respects related to the 

 Neuroptera, appears, as is so often the case with very ancient 

 forms, to connect the two related Orders of the Neuroptera and Or- 

 thoptera. 



I have but little more to say on the Orthoptera. Some of the 

 species are very pugnacious: when two male field-crickets 

 (Gryllus campestris) are confined together, they fight till one kills 

 the other; and the species of Mantis are described as maneuvering 

 ■with their sword-like front-limbs, like hussars with their sabres. 

 The Chinese keep these insects in little bamboo cages, and match 

 them like game-cocks.* With respect to color, some exotic locusts 

 are beautifully ornamented; the posterior wings being marked 

 with red, blue, and black; but as throughout the Order the sexes 

 rarely differ much in color, it is not probable that they owe their 



«2 Landois has recently found in certain Orthoptera rudimentary 

 structures closely similar to the sound-producing organs in the Ho- 

 moptera; and this is a surprising fact. See 'Zeitschr. fur wissensch. 

 Zoolog.' B. xxli. Heft 3, 1S71, p. 348. 



" 'Transact. Ent. Sec' 3rd series, vol. ii. ('Journal cf Proceedings,' 

 p. U7.) 



» Westwood, 'Modern Class, of Insects,' vol. i. p. 427; for crickets, 

 p. 445. 



