326 TEXT-BOOK OF ZOOLOGY 



important fertilizers (pollinators) of flowers. By means of their very 

 long proboscis they are enabled to penetrate into very long and narrow 

 tubes, which other insects, having a short proboscis, are unable to 

 probe (see especially Sphingidse). 



4. The insect discovers the source of the honey by means of its large 

 hemispherical eyes, and its organs of smell situated in the long thread-like 

 antennae, which present club-shaped thickenings at their extremities. 



Other Butterflies. 



All of these, like the white cabbage butterfly, fly during the warm 

 hours of sunshine. All of them, too, in settling down fold their wings 

 vertically. Accordingly, we find that in all of them the upper side of the 

 wing is decorated with brilliant colours, while the under surface is invariably 

 of a colour ivhich presents little contrast to the insect's surroundings, and 

 thereby hides it from the sight of its enemies. To what an extent this 

 "protective colouring" maybe developed is seen in the Indian and 

 Sumatran genus Kallima. In this butterfly the upper side of the wing 

 is resplendent in black, orange, iridescent blue and various shades of 

 brown, the whole forming a very beautiful colour pattern. When, how- 

 ever, the insect settles in the bushes the colours disappear as if by magic. 

 With its wings folded together, the butterfly now exactly resembles a 

 faded leaf, the under side of the wing being of a dirty brown colour, while 

 a dark stripe bears a deceptive resemblance to the midrib of the leaf, 

 and a prolongation of the hind-wing represents the leaf-stalk. Moreover, 

 when at rest the insect sits with its body and antennae hidden between 

 the wings, and thereby by its entire outline still further heightens the 

 resemblance to a leaf. 



Though our insects do not supply us with so characteristic an 

 instance of protective colouring, many of our species display this 

 phenomenon, though it is less marked in the Whites (Pieris) than in 

 other species (see white cabbage butterfly, Section D, 1 b). The Small 

 White (P. rapes) resembles the large white in all points. It, however, 

 deposits its eggs singly on cruciferous plants and mignonette. The 

 larva is of a dirty green colour, and when sitting on the stalk of 

 mignonette can scarcely be distinguished. 



The Black- Veined White (P. cratcegi) has fine, perfectly white wings, 

 the veins, however, being black. In many districts this insect has 

 for many years entirely disappeared. This is, however, by no means 

 to be regretted ; for the caterpillars, which hibernate in silky nests or 

 " tents " of their own construction (see the brown-tail moth), are very 

 destructive to fruit-trees. Two other well-known species of Whites are 



