1900.] INSECTS OF THE " SKEAT EXPEDITION." 861 



to the word " riang " (to call back) pronounced very rapidly and 

 repeatedly. All four species of beetle are on sale for food in the 

 local markets of Patalung, and their grubs, which are found in 

 the earth or under fallen trees, are eaten also. (A conventional 

 representation of the grubs is often carved on rice-stirrers and 

 other objects of household use by the Malays, who call them " Ulat 

 KiJci") Both beetles and Cicadse are either boiled or fried in 

 cocoanut-oil. The latter have very little flavour of any sort, and 

 what they have is vegetable rather than animal. 



Remarks. — The existence of auditory organs in the Cicadse has 

 not been demonstrated with certainty. The insects must indeed 

 be deaf if they mistake the sound of clapping for the squeaky 

 whirr of the male's stridulation. It is evident, however, that the 

 females have some perception of rhythm, if not of sound. May 

 not this perception be due to vibrations produced in the opercula 

 of the stridulating apparatus ? The opercula are often well 

 developed in the voiceless females, though they differ in shape from 

 those of the males. The males, supposing that the perceptive 

 organ were situated in the stridulating apparatus, would be 

 deafened by their own song ; as Sharp points out when dealing 

 with Swinton's theory that one of the membranes of the apparatus 

 itself, a membrane which apparently is only present in the male, 

 is an auditory organ. But there is no need for the males to hear 

 their own song, and no proof that they do so. Though only one 

 species of Cicada is attracted by the particular rhythm with which 

 the people of Patalung clap their hands, another rhythm might 

 attract another form. The several species of Cicadse inhabiting 

 the same country undoubtedly sing in different rhythm : from one 

 another. The song of this species is fairly monotonous and 

 unbroken, though it rises and falls to a slight extent. That of the 

 large form Pomponia imperatoria, which restricts itself to deep 

 jungle, rises in a series of trills, each of which concludes with a 

 kind of click. Each section of the song is faster, louder, and 

 clearer than the one which preceded it ; until, about five minutes 

 after the Cicada's settling, the noise suddenly comes to an end, as 

 the insect flies off to another tree, where it commences again. 

 The sound produced by this species is, at the beginning of the 

 song, like the winding-up of a large clock, and ends by being 

 comparable to the notes of a penny whistle. Another insect, 

 commonly heard at night in the jungle, presumably also a Cicada, 

 has a clear, loud, clarion-like call which can be heard for a great 

 distance. 



The sounds in a Malayan jungle after dark may justly be com- 

 pared to those in the machinery-hall of an exhibition at the busiest 

 time of day, and their volume increases materially before the coming 

 of dawn. The body of the din is the work of small Cicadse, like the 

 edible species, but the true riang-riang and certain Locustids have 

 no mean share in its production. In some places the " Singing 



1 See Riley, Proe. Amer. Assoc. Adv. Science, vol. xsiv. p. 331. 



