— IG - 



über. «In the organisation of the mouth the same parts exist 

 in Diptera as in the preceding orders», sagt Newport (903), 

 «but modified in form to adapt them to a différent mode of 

 use. Thus we have seen that in Hymenoptera and Lepi- 

 doplera it was simply necessary that the parts should be 

 elongated, to enable the insects to obtain the liquid food 

 already prepared for them; but in Diptera not merely was 

 it necessary that this should be the case, but also that 

 their form should be materially altered, to adapt them 

 to a mode of employment different from that of analogous 

 parts in other insects. Thus in Та^ашс^б^/?, thelabrumand 

 mandibles are used like lancets, to pierce the integuments 

 of other animals, before these parasitic bloodsuckers can 

 obtain the living fluid they are in quest of; while in other 

 species, as in Eristalis floreus, which subsists both on 

 the pollen and honey of flowers, the mandibles and ma- 

 xillae are employed to scrape off the pollen from the an- 

 thers, before it is conveyed along the tube formed by the 

 united parts of the mouth to the pharynx. In other Dip- 

 tera, of which the food is entirely fluid and easily ac- 

 cessible, as in the common house-flies, Muscidae, all the 

 parts of the mouth are soft and fleshy, and simply adap- 

 ted to form a sucking tube, which in a state of rest is 

 closely folded up in a deep fissure, on the under surface 

 of the head, formed by the two sides of the clypeus. On 

 the other hand, in the Oestridae, which, as we have seen 

 in the Phryrjanidae, Bombycidae, and others that take 

 no food in their perfect state, all the parts of the mouth 

 have entirely disappeared.» 



Ich habe mit Fleiss diese Stelle angeführt, um den Le- 

 ser mit Newport's Ansicht über die Gründe der Um- 

 wandlung der Mundtheile der Insekten bekannt zu ma- 

 chen. Wie aus dem eben angeführten Gitate zu ersehen ist, 



