D ADD Y-LONG-LEGS 223 



The larval or grub phase of life is passed by many of 

 these flies in the earth amidst putrefying vegetable and 

 animal refuse on which they feed, as in the instance of 

 the daddy-long-legs ; but here and there we find species 

 which penetrate into the soft parts of plants and animals. 

 A whole group of many species burrow into mushrooms 

 and other fungi when they are grubs ; others, again, live 

 in water when they are grubs or " larvae," and have a 

 very active aquatic life, rising to the surface to breathe 

 air and searching for food in the water with their feelers 

 and eyes, and seizing it with their powerful jaws. The 

 mother fly in these cases lays her eggs in a group on the 

 surface of the water or embedded in a jelly which she 

 secretes and attaches to the leaves of water plants. 

 Some of the short-horned flies (bott-flies and others) lay 

 their eggs in the living flesh of warm-blooded animals, 

 including man, and the maggots hatch there and feed on 

 the juices of the " flyblown " animal. Cases are not rare 

 of children being thus infested. 



The black flies which fly in swarms " high " or " low " 

 in the country lanes on summer evenings are not true 

 biting gnats, but a large kind of midges known as 

 Chironomus or Harlequin flies. Their eggs are laid 

 in the water of ponds, and the larvae on hatching bury 

 themselves in the rich black mud and feed there. The 

 larvae are of a splendid blood-red colour, and are often 

 called " blood-worms." They owe their colour to the 

 presence in their blood of the same red oxygen-seizing 

 crystallizable substance, haemoglobin, which gives its 

 red colour to the blood of man and other vertebrates. 

 Its presence is remarkable, because in all other insects 

 the blood is colourless or of pale blue or green tint. 

 It seems that this haemoglobin renders service to the 

 larvae of the big midges as it does to some other 



