1900.] INSECTS OF THE " SKEAT EXPEDITION." 859 



the former the exhibition of brilliant colour is primarily a sexual 

 attraction, being better developed in the male than it is in the 

 female ; but it seems probable that even in Liolepis any excite- 

 ment may cause a display, and that in a secondary manner this 

 display has come to be used as a means of alarming enemies, 

 though it will be noticed that the conspicuous stripes are not 

 exhibited suddenly, or immediately on disturbance, but only when 

 the animal is handled. Also it is strange if the larger, more active 

 male has this means of defence better developed than the female, 

 which must be much less agile at times. The fact that Liolepis 

 bellii has particularly strong teeth and jaws does not seem to me 

 to be of any importance in considering the case. The Cobra affords 

 one of the best instances of alarming coloration and attitude, and 

 it happens to be a particularly venomous animal ; but there are 

 instances of similar display among animals which have no such 

 dangerous qualities. 



The black-and-yellow Snake, Dipsadomorphus dendrophilus, 

 which is the commonest large Snake in Lower Siam, when driven 

 to extremities exhibits movements which may be compared with 

 the sudden display of colour by other forms. If a specimen of 

 this Snake is tied up so that it cannot escape, it raises its head, 

 gapes, hisses, strikes wildly at anything that is held near it, and 

 drums spasmodically upon the ground with the last few joints of 

 its tail, thus producing a curious noise. But I have never seen it 

 bite, even when a stick was held close to its mouth ; though many 

 Snakes, e. g. Coluber tceniurus, will snap at anything, even at their 

 own bodies, when they are sufficiently enraged. The Malays say 

 that Dipsadomorphus is not poisonous ; but they are much afraid 

 of its bite, because of its violent appearance. 



V. Sounds peoduced by Insects. 

 A Cicada (Dundubia intemerata). 



There are two distinct colour varieties of this species, found 

 together and independent of sex ; the body of one being grass- 

 green, and that of the other pale brown, which becomes yellow as 

 the insect dries. Among my dried specimens there are inter- 

 mediate forms more or less mottled ; but this peculiarity did not 

 appear for some days after death, and in life all the individuals 

 were either one colour or the other. 



At certain seasons this Cicada forms a regular article of diet 

 among the Siamese inhabitants of Patalung ; and as their method 

 of capturing it is based upon a knowledge of its habits, I cannot 

 do better than give an account of this method, as I saw in opera- 

 tion at Ban Nab, a village on the border of the hill-country of 

 Patalung. Immediately after the sun had set several of the 

 natives gathered in an open space, round a fire of brushwood or a 

 number of torches fastened to stakes stuck into the ground, and 

 commenced to clap their hands in unison, observing a regular time 

 and rhythm. Very soon, if they were fortunate, the Cicadas flew 



