464 THE CANADIAN NATURALIST. [Yol. X. 



When the instruments are inserted into the flesh, the proboscis 

 is pushed back at an angle more or less acute, and having some- 

 what the appearance of a leg with a bent joint. 



The mandibles have been modified into a pair of extremely 

 small and beautiful^ saws, whose sharp teeth, generally ten or 

 twelve in number, occupy about one-twelfth to one-fifteenth of 

 the length of the proboscis, the teeth are small at the point of the 

 instrument but they increase in size to about the middle of the 

 saw, and being set backwards, they not only act as cutting tools, 

 but from their barbed shape, give the creature the "purchase" 

 necessary to hold it to its prey. 



A careful observation of the insect, while feedina- shows it 

 pulling the saw on one side, as it pushes in the saw on the oppo- 

 site side. The saw that it pulls is the saw that cuts ; thus the 

 action that increases the depth and size of the wound also gives 

 the creature the necessary "purchase" to enable it to push 

 in the opposite saw. 



Between these saws and the tube or sucker, the maxillae are 

 modified into a pair of irritators (these are horny and stiff like 

 bristles) supposed to be used to excite and increase the flow of 

 blood, and possibly used also to prevent any solid matter enter- 

 ing the tube in drawing or sucking up the blood. 



The sucking tube is a modification of the tongue, is horny in 

 structure, sharp pointed and solid at the end, so that it may be 

 pressed firmly against the bottom of the wound without the risk 

 of being stopped up, as it might be if the orifice was at the end, 

 the blood flowing through a hole like the eye of a needle, which 

 opens into the tube at a distance from the point equal to about 

 the diameter of the tube. 



In conclusion, I have only to add that in the feeding appar- 

 atus of the mosquito, we have a beautiful illustration of a perfect 

 and wonderful adaptation of means to ends. 



