RHOPALOCERA MALAYAN A. 195 



when we remember the small size of the butterflies aucl their cousequent somewhat neglected 

 structural examination.* 



Of their habits there are many scattered notes recorded which still rc(juire the aid of the 

 assiduous collector and responsible editor. The curious habit of rubbing tlie erect posterior 

 wings together has been noticed by many observers, and notably by Mr. Wallace, who, in the 

 Amazon Valley, describes the wings as having the "appearance of revolving discs," f and by 

 Mr. Trimen, who, in South Africa, represents the action of the wings as "resembling that of 

 the blades of a pair of scissors when repeatedly opened and shut." \ This curious habit has 

 been explained by Mr. Swinton, who has paid much and painstaking attention to the subject, as 

 due to the process of " stridulation." § Although these small and exquisite butterflies are so 

 brilliantly coloured, they yet, when at rest and with the under surface of their wings alone 

 exposed, approximate very closely to the plants on which they settle, as instanced by 

 Mr. Uhler, who, when collecting in Eastern Colorado, noticed two species which settled on an 

 abundant " delicately blue lupin," and which when at rest on these flowers "were very diflicult 

 to recognise." || 



Some species seem to have a definite time of day for their appearance, but the evidence 

 is too voluminous for insertion here, but examples are afforded by the statement of Lieut. 

 Gervase F. Mathew that in England Lijcama arion " is a butterfly that does not fly much after 

 mid-day, "H whilst in India, according to a recent writer,*^ " when the afternoon is drawing 

 on, then many a rich Hair-streak will appear, and, taking its station in the middle of some 

 large leaf, will open its wings just a little, and give you a peep of the dazzling blue within." f f 



We are also indebted to that excellent and trustworthy observer Mr. P. H. Gosse for 

 some interesting details obtained in North America. Referring to " rohjommatus pseudanjiolus," 

 he writes: — "In appearance and manner it much resembles the delicate little Hair-streaks 

 (Thecla) with which it associates. Like them it appears to be very pugnacious, attacking with 

 Quixotic knight-errantry any intruder, no matter how much bigger than itself. It is particularly 

 gamesome a few hours after sunrise ; taking its stand on some prominent leaf of a bush, 

 it rushes out upon every butterfly that passes by ; then they perform such swift and tortuous 

 evolutions that the eye is unable to follow them : this lasts only for a few seconds ; for having 

 pursued the traveUer three or four yards, the Polijommatus returns to the very same leaf to 

 watch as before. All this, however, I believe is done in a spirit of play, and not with any 



* Some good lepidopterists, however, have taken a very opposite and synthetic view on this question, as, for example, 

 Mr. Herman Strecker, who is, or was, of opinion that there was no reason " why all the N. American and Em'opean species, 

 except the few contained in Eumacus, Hiibn., should not be embraced within one genus, even including the Theclas" (Lepid. 

 Ehopal. & Heteroc. p. 81 (1874), and Mr. Kirby is also of opinion that "the number of distinctly-defined genera is small" 

 (Europ. Butt. & Moths, p. 44). 



t Trans. Ent. Soc. 1859, p. iJ63. | Ehop. Afr. Austr. p. 218. 



§ 'Insect Variety,' p. 118. || Bull. Unit. States Geol. & Geogr. Surv. iii. p. 355 (1877). 



IT ' Entomologist,' vol. s. p. 71. ** Eha, ' The Tribes on my Frontier,' p. 108. 



ff This limited and punctual appearance of many insects is an interesting and peculiar pliase which has scarcely received 

 the notice that might have been expected. Even on Penang Hill, I found it reported that various species of Cicadidw had 

 different and set times of day at which to exert their " musical" efforts. But this did not escape the attention of the great and 

 eloquent Humboldt, who, when giving the account of his memorable journey, forcibly remarks : — " We have seen that the insects 

 of the tropics everywhere follow a certain standard in the periods at which they alternately arrive and disappear. At fixed and 

 invariable hours, in the same season, and the same latitude, the air is peopled with new inhabitants, and in a zone where the 

 barometer becomes a clock, where everything proceeds with such admu-able regularity, we might guess, blindfold, the hour of 

 the day or night by the hum of the insects and by their stings " (' Personal Narrative ' (Eng. trausL), vol. ii. p. 277). 



