52 THE CAUSES WHICH PEOPAGATE 



connection, exist on the first median nervure of the hind wing in a 

 few species ; both being- seen in the tawny Danais, that extends 

 its range to Southern Europe. Others of the Ithonia group 

 have a tuft of long hair near the anterior margin of the hind 

 wings, sometimes common to the sexes, and flavouring of vanilla, 

 while the males have a brown spot covered by the tuft. The 

 spot and brush of the Yellow Callidryas are reproduced in one of 

 the Satyrinse, and in some of the Nymphalinse ; while in the 

 m.ale of the blue Ag^ronia Arefhusa a rather strong odour is 

 emitted by two large brown spots, situated between the wings, 

 which appear absent in others of this musical genus. The 

 glorious blue satin Morphos, the pride of Brazilian forest trees, 

 have protrusible hemispherical anal appendages, which some- 

 times are odoriferous of vanilla ; and in the Brassolinse, another 

 bulky South American j^rogeny, pencils of erectile hairs or spots 

 of scales are present. So, too, the peculiar long-winged Heli- 

 coninse of the glades have scent organs in the male, situated 

 between the anal valves, and in the female these are placed on 

 the dorsal side of the abdominal extremity ; but some have also 

 a scent-brush, if conclusion may be drawn from a figure in the 

 volume on ^' Foreign Butterflies,-'-' belonging to the Naturalist's 

 Library series. 



But Bidonis Biblis, according to Dr. Miiller, is, so far as odours 

 are concerned, the most interesting of all these fairy-formed and 

 many-coloured things of the tropical bush. On seizing one of 

 these butterflies of either sex, it pushes from between the fourth 

 and fifth segment of the abdomen two hemispherical protu- 

 berances producing a disagreeable odour; and the male has a 

 second pair between the fifth and sixth segments of the 

 abdomen, while a different musk-like odour is j^roduced by a 

 black sj)ot beneath the front wings. In the tailed Hair Streaks 

 the sexual spot that may be seen on the disc of the front wings 

 of the female of our green sort, is said to be odorous; and if 

 so, this is a singular instance of a scent secretion supplanting 

 a fixed wing colour. 



The Skipper Butterflies, diurnal over our northern hills and 

 woodland, amid the scorching tropical glare are known as 

 evening visitors, stealing mysteriously to hang at the garden 

 lupins in purple dusk, before a reflex light has awoke a second 



