24 THE BOOK OF THE FLY 



scent and are easily captured when attacking human 

 beings ; they alight on their victims with a stealthy 

 silent approach. They appear unable to discriminate 

 between clothing and bare skin as suitable spots for 

 feeding. Amongst a band of mountaineering pedes- 

 trians, on a sunny day, it was observable that there 

 would be a dozen or more "blinden breeze-flies" 

 settling on the back of one, whilst the rest of the party 

 were only favoured now and then by one or two apiece. 

 It was apparently the smell of the " home-spun " coat 

 which attracted ; the colour of the garment did not 

 seem to be the cause of the selection. Sunshine loving 

 flies prefer white and pale colours. If a dog could 

 speak, he would explain the smell of some " finished " 

 cloth, but, for the sake of the fastidious, the secret is 

 not here disclosed. 



Very closely allied to the true breeze-flies in habit of 

 life are the species of the genus Chrysops, of which 

 two only are often met with in England, namely 

 Ch. ccecutiens and Ch. relicta ; these flies are very 

 keen blood suckers; they are smaller, slightly more 

 slender and brighter coloured than the commoner 

 Tabanidce ; it is characteristic of the genus Chrysops that 

 the antennae are quite twice the length of the remarkably 

 short horns of the majority of common full-bodied 

 flies ; all the species possess beautiful golden glittering 

 eyes (whence the name Chrysops), and their wings are 

 spotted and tinted. 



One of the most horribly disgusting but serious facts 

 connected with flies is observable most conspicuously 

 amongst the wondrous family of the CEstridcs. These 

 pass the larval stage of life, not on, but inside the 



