388 INSECTS AT TIOME. 



wliincbats, stonechats, whitethroats, and other sedge and grass- 

 loving birds. A swift foot soon brought the aerial object near; 

 then came the sudden switch and the simultaneous drop — a sign 

 that all was right. The fall into a sitting posture was the 

 natural, necessitous, and happily convenient move, for directly 

 the capture was made our legs lost all power, and suggested a 

 seat on the fen as the right position for pinning the prize ; 

 and so it was. 



' Experience taught me these lessons in the capture of the 

 Swallow-tail. When in the neighbourhood of flowers, take it 

 gently ; move slowly up to the insect, and when within a 

 couple of yards secure it with a dash. This is all easy enough ; 

 but when forced into a smart chase over the fen, the following 

 manoeuvre proved successful. I found that the pursued insect, 

 after a long flight, generally branched off at a right angle ; so 

 that if I kept a respectful distance behind, and when it altered 

 its course turned at an acute angle in the same direction, I was 

 fortunate enough to meet the object of my chase, so that the 

 Butterfly and I formed a right-angled triangle. Intelligisne ? 

 I think the description clear, though it may perhaps smell a 

 little of the mathematical odour of the 'Varsity. We caught in 

 the two hours thirty-five specimens, one of wliich I send here- 

 with. Several, however, were much worn ; no doubt through 

 creeping about in the herbage during the preceding unfavour- 

 able weather for flight. My brother obtained eleven larvae 

 from the same spot last year. All the pupse have not yet dis- 

 gorged their contents. An imago gladdens my eyes every now 

 and then. Several of the specimens have slightly difi'erent 

 markings. One, however, has the hind margins of the under 

 wings lightly coloured with the same chestnut-red hue which 

 composes the prevailing tint in the large spot close to the anal 

 angle of each wing ; a unique variety, I believe.' 



The egg of this insect is light green in colour and oval in 

 shape. It may seem rather superfluous to say that an egg is 

 oval in shape, but we shall presently see that many eggs of 

 Butterflies are anything but oval in shape. Just before the 

 egg is hatched, its colour darkens until it is nearly black, which 

 in fact is the colour of the young caterpillar. As soon as the 

 larva is hatched, it eats the shell of the egg in which it has 

 been developed, and after every change of skin it eats in like 



