OF LEPIDOPTEROUS INSECTS. 101 



its habits, that it seldom leaves the field on which it 

 is bred, although hundreds of them may be seen 

 flying low, and frequently alighting on plants. This 

 insect was only found by him at Wilsden, near 

 Harrow-on-the Hill ; but recent collectors have been 

 unable to detect it there. 



These local associations seem rather to be unusual 

 to the general law which regulates the motions of 

 lepidopterous insects, for almost the whole tribe, 

 particularly the papilionaceous genera, seem to rove 

 from field to field, without any fixed plan or motive. 

 As their wings are usually so ample, we need not 

 wonder that the lepidopterous insects are such excel- 

 lent fliers. Indeed, they seem to flit untired from . 

 flower to flower, and from field to field ; impelled at 

 one time by hunger, and another by love or maternal 

 solicitude. The distance to which some males will 

 fly is truly astonishing. One of the Silkworm 

 Moths (Bombyx paphia of Fabricius) is stated to 

 travel sometimes more than a hundred miles in this 

 way.* 



The most beautiful of all the British butterflies, 

 the Purple Emperor, (Papilio iris of Linnaeus,) when 

 he makes his first appearance, fixes his throne on the 

 summit of some lofty oak, from whence, in sunny 

 days, unattended by his empress, who does not fly, 

 he takes his excursions. Lanching into the air, 

 from one of the highest twigs, he mounts often to so 

 great a height, as to become invisible. Hence his 



* Linncean Transactions, vol. vii. p. 40. 



