226 



PARASITES. 



trate the flesh, the labium becomes more and more elbowed, so as 

 to shorten it, without ceasing to support the piercing parts. When 

 these acts have been completed, the creature proceeds to draw the 

 blood into its mouth, the sucking bulb of the oesophagus (which is 

 furnished with a valve) acts, and the victim makes a few cursory 

 remarks which scarcely come within the scope of this paper. 



According to the accounts of travellers, these pests seem to be 

 almost omnipresent, extending from the tropics to the poles. 

 Brehm, in his interesting book. From North Pole to Equator^ gives 

 a most graphic account of the mosquitoes of the "tundra" around 

 the North Pole. He says : — " To call it the most important living 

 creature of the tundra would be scarcely an exaggeration. It 

 enables not a few of the higher animals, especially birds and fishes, 

 to live. It forces others, like man, to periodic wanderings, and it 

 is in itself enough to make the tundra uninhabitable in summer by 

 civilised beings. Its numbers are beyond conception ; its power 

 conquers man and beast ; the torture it causes beggars descrip- 

 tion." He goes on to say : — " If an observer can so far restrain 

 himself as to watch them at this work of blood, without driving 

 them away or disturbing them, he notices that neither their settling 

 or moving about is felt in the least. Immediately after alighting 

 they set to work. Leisurely they walk up and down on the skin, 

 carefully feeling it with their proboscis ; suddenly they stand still, 

 and with surprising ease pierce the skin. 



" While they suck, they lift up one of the hind legs and wave 

 it, with evident satisfaction, backwards and forwards — the more 

 emphatically, the more the translucent body becomes filled with 

 blood. As soon as they have tasted blood they pay no heed to 

 anything else, and seem scarcely to feel, though they are molested 

 and tortured. If one draws the proboscis out of the wound with 

 forceps, they feel about for a moment, and then bore again in the 

 same or a new place ; if one cuts the proboscis quickly through 

 with sharp scissors, they usually remain still, as if they must think 

 for a minute, then pass the forelegs gently over the remaining 

 portion, and make a prolonged examination to assure themselves 

 that the organ is no longer present. If one suddenly cuts off one 

 of their hind legs, they go on sucking as if nothing had happened, 

 and continue to move the stump ; if one cuts the blood-filled body 



