52 INSECTS. 



the food of the vast hordes of them that frequent the tropics. It is true that the 

 females alone bite ; but the proboscis is a highly perfected organ for piercing and 

 sucking, and it might be supposed that it is extensively used for the purpose. Yet 

 it has been pointed out that the vast majority of mosquitoes can never taste 

 mammalian blood. In various places, such as parts of India for example, 

 mosquitoes are found in swarms in spots never visited by human, beings, and in 

 which there are no large mammals. It has been suggested that, failing to obtain 

 blood, mosquitoes support themselves on the juices of plants, but no observations 

 in support of this have been recorded. 



The daddy long-legs (TipuLidce) contain the finest species of this 



division of the order ; the largest European form being the giant 

 daddy long-legs (Tipula gigantea), which has its wings clouded with brown, and 

 measures about 1J inches in length. Much larger kinds are, however, met with in 

 Burma and China. The short and fleshy proboscis is not adapted for piercing, but 

 merely for absorbing fluids ; and the antennae are not feathery, as is so often the case 

 in the gnats and midges, although in the species of the genus Ctenophora which are 

 of stouter build, and often brightly coloured black and yellow, thereby resembling 

 some of the saw-flies the antenna are pectinated in the male. In this family the 

 eggs are laid and the larvae undergo their growth and change of form either in 

 water or earth. The females of two of the commonest British species (T. 

 oleracea and T. paludosa) may be seen in summer and autumn flying about 

 meadows and depositing their eggs here and there in the soil. When hatched, the 

 larvae start feeding upon the roots of grass and corn, thereby doing considerable 

 damage to farmers and gardeners, to whom they are known by the name, " leather- 

 jackets." 



The true midges belonging to the family ChironomidcB are 



nearly allied to the gnats, with which they are often confounded ; but 

 the mouth-parts are rarely adapted for piercing, the proboscis being short and soft. 

 In the genus Ceratopogon the jaws of the females are, however, lancet-shaped, and 

 capable of drawing blood. The little black midge that in the summer settles upon 

 the hands and face and inflicts a sharp prick belongs to this genus. But the best 

 known member of the family is the plumed midge (Chironormis plumosus), which 

 on summer evenings may be seen dancing in swarms along roads and lanes. Its 

 name has been given to this species on account of the beautiful feathery-like 

 antennas of the male. In connection with this species a case of luminosity has 

 recently been recorded. An observer in Russian Asia found on the shores of Lake 

 Issykkul a number of examples of this midge, and of an allied form belonging to 

 the genus Corethra emitting a phosphorescent light. Failing to discover any 

 luminous organ he came to the conclusion that the light was due to the presence 

 in the insect of multitudes of parasitic bacteria, an opinion strengthened by 

 the observation that the shining individuals were sluggish and never seen on the 

 wing. 



The fungus-midges (Mycetophilidce) take their name from the 



' fact that the larvae of most species feed upon fungi of various kinds. 



The perfect insects, which frequent damp situations, are all of small size, and mostly 



pale in colour. To this family belongs the so-called yellow-fever fly, a species of the 



