A NATURALIST IN BRAZIL 



and the Ithominiae. The Ceratiniae and the Mechanites are mostly 

 small forms of an ochreous yellow, with black veins and light yellow 

 spots on the fore-wings. They include an absolutely incredible 

 number of species, and Wallace long ago reported that new species 

 were often encountered every few miles, and many small areas of 

 forest, not even separated from one another by hills or streams, 

 have their own species, which occur nowhere else. Black, ochre and 

 yellow are the colours likewise of the Lycoreae (Plate 29, I, i), but 

 these are larger insects; while the Heliconius family contains the 

 handsomest forms of this butterfly (Plate 29, I, 4). 



Among them are black butterflies with a blue lustre, and yellow 

 borders to the wings ; others, like Heliconius phyllis, have a large 

 fiery-red patch on the narrow black fore-wings, while a broad 

 yellow streak runs diagonally across the under-wings, a narrower 

 streak crossing the fore-wings. This Heliconius was common in the 

 virgin forest of Pernambuco. These beautiful soberly-coloured 

 creatures, flying slowly over the ground or the undergrowth, 

 apparently without ever moving their wings, contributed not a little 

 to the atmosphere of the glittering forest, adding a dreamy, peaceful 

 note to the majestic scene. 



As a matter of fact. Nature may very well have intended — if for 

 once we may speak in such a fashion — to give the Heliconiinae and 

 other "aeroplane butterflies" a slow flight, and to make them 

 plainly visible by their characteristic markings. For these creatures 

 have a means of protection against the many enemies of their kind, 

 who would otherwise be glad enough to devour them : namely, they 

 have an unpleasant smell, and apparently a bitter and nauseous 

 flavour. I once took a pupa home with me — it was marked with 

 black and yellow — and when a Methone emerged from it, with its 

 black-bordered glassy wings, the glass case smelt as strongly of 

 urine as a fox's earth or a mouse-cage. Now if these butterflies are 

 nauseous it is evidently to their advantage that the enemies of 

 butterflies in general should recognize them immediately. Hence 

 the bright colours and the slow flight, which never conceals the 

 markings ! If a Heliconid were to fly quickly past a bird, and the 

 latter, in the excitement of the chase, were to snap it up, then, even 

 though it at once rejected its acrid prey, the action of the protective 

 measure would be too late. The butterfly must warn its enemies 

 from afar. Now, we find that these butterflies prefer black and 

 yellow, and resemble one another in shape. Consequently a bird 

 has no need to acquire the same unpleasant experience in respect 



218 



