PARTS OF INSECTS, AND MISCELLANEOUS OBJECTS. 



125 



THE PROBOSCIS OF THE OX-FLY. This insect, which is the torment of cattle 

 during the summer months, and nourishes itself upon their blood, is provided 

 with a curious apparatus admirably adapted for piercing the tough hide and im 

 bibing the blood of its victim. The proboscis is shown, of its natural size, in 

 figure 211 ; and a magnified view of the same is presented in figure 212. 



This member is complex in 

 its structure, and is enclosed 

 in a fleshy case, which is re 

 moved in the drawing, in or 

 der that the several parts may 

 be separately exhibited. The 

 parts are six in number, be 

 sides the two feelers, a, a, 

 which are composed of a spon 

 gy substance, fringed with hair. 

 They are of a gray color, and 

 are capable of motion, each 

 being furnished with a joint, Figf211&amp;gt; 

 at the point where it is con- 

 nected with the head. 



The office of these append 

 ages is to protect from harm 

 the delicate parts of the pro 

 boscis, since they are always 



placed on each side of it whenever a puncture is made by the insect. The 

 blades or lancets, 6, 6, are the instruments which inflict the wound : in shape 

 they are alike, each having the form of a broad knife with a sharp point and 

 fine edge, and gradually increasing in thickness towards the back. The parts, 

 c, c, termed piercers, are furnished with teeth like a saw, and are supposed to be 

 employed for the purpose of increasing the size of the wound, and thus obtain 

 ing a more copious supply of blood. It is also imagined, from being of a hard 

 texture, that they likewise serve as a protection to the tube which conveys the 

 blood from the wound to the stomach of the insect, and which would otherwise 

 be liable to receive injury. This tube is seen inclosed in its fleshy case, d, with 

 a lancet and serrated piercer upon either side. 



THE SUCKER OF THE GNAT. The sucker of the gnat appears to the naked 

 eye like a sharp needle, finer than a hair, but under the microscope it presents 

 a complicated structure ; and although it has been minutely examined, the most 

 distinguished observers have differed in respect to the number of parts of which 

 it is composed. Leuwenhoeck enumerates four parts, Swammerdam six, inclu 

 ding the lip, and Reaumur Jive ; but it has been supposed that their observations 

 might possibly have been made either upon mutilated insects, or upon those of 

 different species. As soon as a gnat has settled upon some exposed part of an 



