274 



Marvels of Insect Life. 



a fringe of much longer fleshy spines which stand out straight and horizontally. 

 The slender half, which terminates in the mouth, can be extended to twice its resting 

 length. On the under side there is a double row of short, fleshy feet covered with 

 hooked bristles, which cannot be seen until the grub is turned upon its back. At 

 the rear-end on the upper side will be seen a double coronet, or rather two coronets 

 side by side. These are the openings to the breathing organs of the grub. As 

 we have already shown, in most Insects the spiracles or breathing holes are situated 

 along the sides, but clearly this arrangement would be useless to a grub whose 

 sides are pressed tightly against the walls of the wasp-cells. The only available 

 place for an intake of fresh air is this last segment of the body, which acts as a stopper 

 to the cell that the grub is cleaning out ; and here it is placed. The creature has no 

 head, no eyes, only a mouth. 



The chrysalis is much like the grub at a glance, but here the broader end is the 



front, and the position 

 of the breathing organ is 

 changed. Instead of the 

 two coronets on the last 

 segment, we 

 short curved 

 behind the 

 truth, the 



appearance is 

 and due to 

 chrysalis bein 



--^-r- 



two 



just 



In 



Photo bv] 



In its banding of yd 



have 

 horns 

 head. 



external 



deceptive 



the real 



g covered 



by the skin of the grub. 



Within, the chrysalis 



shows all the parts of 



the future fiy folded 



close to the body. 



The fly that emerges 

 is about three-quarters of 

 an inch in length, reckon- 

 ing from the base of the 

 antennae to the tips of the closed wings. In general appearance there is not 

 the remotest likeness to a wasp as one would expect to find on the basis of 

 the teleological view of the humble-bee's drone-fly. As a matter of fact when the fly 

 comes indoors, as it frequently does, it is always taken for a honey-bee. The large 

 compound eyes are dark purple-brown, and cover almost the whole of the upper 

 part of the head. Slightly separating them is a golden-brown interval which 

 broadens in front and becomes downy. The antennae are short, stout, three-jointed 

 clubs, the first joint bearing a mucli longer feather-like branch. The fore-body is black, 

 as also the terminal half of the hind-body. The basal half of the hind-body is white 

 and pellucid. There is a smoky patch on the fore-edge of the wings, and when these 

 arc closed the dark patches correspond in position with the dark portion of the 

 body beneath them and have the effect of widening it. In this stage of its existence 



[E. Step, F.r..s. 

 Girdled Drone-Fly. 



uid black this spocies approaches to a colour resemblance to the 

 wasp, but the form of its body is quite dit^ferent: and it may be concluded that its liverv 

 is not intended to deceive its friend, the wasp, but to act as a warning signal to possible 

 enemies — black and yellow strongly contrasted being a coimnon sign that the Insect is 

 not edible. 



