PARTS or IXSF.CTS. 33 



tions; and so likewise do the appendices at the extremity of the ab- 

 domen. 



The abdomen contains the intestines, the ovary, and part of the or- 

 gans of res))iration : it is affixed to tlie thorax, and in most insects di- 

 stinct from it, forming the posterior part of the Ijody. 



Cauda, the Tail. An appendage of any kind terminating the abdomen 

 is usnally denominated tlie tail. Tliese appendages vary in tignre con- 

 siderably in different insects, and many tribes are totally destitute of them. 

 They are supposed to be destined to direct the motion of the insect in 

 flight, to serve ibr its defence, and for the deposition of its eggs. In some 

 insects this tail is simple, and yet capable of being extended and with- 

 drawn at pleasure ; in otliers elongated. Some are setaceous or bris- 

 tle-shaped, as in the Rap/iidia. Those termed triseta have three bristle^ 

 shaped appendices, as in the Ep/temera. In some it is forked, as in 

 Fodura. When it terminates in a pair of forceps it is called J'orciputa. 

 In the Bhdta and others it is Jhlioaa, or resembling a leaf. In the 

 Panorpa it is furnished with a sting, and is called tclijira : this last may 

 be more properly referred to the next. 



AcuLEus, the Stiijg : an instrument with which insects wound and in- 

 stil a poison. The sting generally proceeds from the under part of the 

 last ring of the belly : in some it is sharp and pointed, in others ser- 

 raied or barbed. It is used by many insects both as an offensive and 

 defensive weapon : by others it is used only to pierce wood, or the 

 bodies of animals, in order to dej^osit their eggs. In wasps and bees 

 the sting is known to be retractile. In some insects it exists in the male 

 only, and in others nature has provided the female alone with 

 this instrument : it is not frequently met with in both sexes of the 

 same species, and the far greater number of insects have no such 

 organ. 



ARTUS, the Members. 



Pedes, the Legs. In all insects the legs amount to six, and never 

 exceed that number ; and the same is observable of the true feet in the 

 larvae of those insects ; the latter have spurious feet to a greater amount, 

 but the true feet do not exceed six. 



The leg of an insect may be divided into four, or more correctly in- 

 to five, parts: Coxa, the first joint or haunch, at the base; Femur, the 

 thigh; Tibia,the shank; Tarsus, the foot; and Unguis, the claw. Each 

 of these parts is enveloped in a hard case of a horny substance, and 

 varies in shape in different insects, the form of the feet in all the kinds 

 being admirably adapted to their mode of life and convenience of their 

 motion, from the different conformations of these limbs it is easy to 

 recognise, even in the dead inbcct, the mode of life which the species is 

 destined by nature to pursue. Those which have the legs adapted for 

 running or walking have them long and cylindrical : the thighs of the 



c 



