814 HYMEN 



robust ;" the ibia, or shank, which is more slender, 

 and terminated by one or two spurs ; and the arti- 

 culated tarsus, which constantly consists of five joints, 

 the fifth being of a conical form, the extremity being 

 the thickest part, and furnished with two strong but 

 small claws, between which the pulvilli, or cushions, 

 are often to be observed. These legs, which are, in 

 feet, the chief organs whereby the insects are enabled 

 to carry on their varied economy and habits, are neces- 

 sarily very varied in their form, and in the appen- 

 dages with which they are furnished. The abdomen, 

 which is also of a very varied form, is attached to 

 the posterior part of the thorax, either by its entire 

 width, in which case it is said to be sessile, or by 

 means of a slender peduncle, or foot-stalk, which in 

 some groups is also long as the abdomen itself. At 

 the extremity of this abdomen, on its lower surface, 

 is attached the ovipositor, saw, or sting above men- 

 tioned, each of which, although varied in form, so as 

 to suit its intended uses, is but! a modification of the 

 same instrument. From the centre of the underside 

 of the abdomen, near its extremity, arise two plates, 

 each consisting of two joints, sometimes valvular, 

 and together forming a scabbard, sometimes more 

 slender, and resembling palpi, and sometimes very 

 long ; between these plates (which are figured in our 

 first vol. p. 362, col. 2, fig. 1 and 2, as they exist in 

 the bee, under the form of two flattened plates, with 

 a pair of small terminal lobes) arise two other pieces, 

 which are very slender, serrated at the tip in the bees, 

 (fig. 8 and 5), but much broader in the saw-flies, and 

 transversely striated, forming the saws with which 

 these insects are provided ; moreover, these two 

 pieces are received, in the bees, into a canal (fig. 2 

 and 4), but in the saw-flies this gutter is broad, 

 flattened, and divided into two separated parts, form- 

 ing the backs of the two saws. In the ichneumons, 

 these various parts are so slender, that at first sight 

 they appear to consist but of a single piece ; on more 

 minutely examining the instrument, however, it will 

 be found that it consists of a scabbard, composed of 

 two pieces, inclosing a fine hair-like bristle, which is, 

 in fact, the exact analogue of the stinging part of the 

 bee's sting, consisting of three pieces. 



These insects, which constitute the fifth Linnaean 

 order, are unquestionably the most interesting of the 

 insect tribes, comprising as they do the bee, wasp, ant, 

 sand-wasp, cuckoo-flies, and saw-flies ; the economy 

 of which is so remarkable, that it has attracted the 

 curiosity of the most uninquisitive persons. Their 

 colours are seldom brilliant ; brown, yellow, black, or 

 grey, being their prevailing tints ; neither do they 

 often acquire a large size, the majority being under an 

 inch in length, and some being so exceedingly minute 

 as to be invisible to the naked eye, except when seen 

 creeping against the light upon a window. Many of 

 the species live in societies more or less numerous, as 

 the bees, ants, and wasps ; these assemblages con- 

 sisting of males and females, and neuters, the latter 

 being abortive females, and destined to perform the 

 more laborious duties of the communityt Others, as 

 the sand-wasps, &c., are solitary in their habits, but 

 their economy is not less interesting than that of the 

 former ; since, although not exhibiting such a variety 

 of remarkable physiological traits, the construction of 

 a nest, and the provisioning it with a supply of food 

 for the young when hatched, by a single insect, is 

 sufficient to prove that the instincts of that insect are 

 not less developed than in cases where a particular 



OPTERA. 



duty devolves upon a particular set of individuals. 

 We have already, in our articles ANT, BEE, CERCE- 

 RID.S:, FoRMicioae.HoRNET, &c., detailed many of the 

 more prominent features in the economy of those 

 insects, which it will be unnecessary to repeat in this 

 place. From these we find that the food laid up in 

 store by one class of these insects, consists of honey 

 collected from flowers ; whilst in another class it con- 

 sists of insects deposited in cells by the parent fly. 

 Another class have the instinct to deposit their eggs 

 in the already provisioned cells of the working classes, 

 the young of which latter are starved to death by the 

 previous exclusion of the parasitic grub, which devours 

 the supply provided for the former. Another class is 

 parasitic in a different sense of the word, depositing 

 their eggs upon or within the bodies of other insects, 

 chiefly in the larva state, the intestines of which are 

 prej'ed upon by the grubs when hatched. Others 

 deposit their eggs in the leaves or stems of various 

 plants, together with an irritating matter, which causes 

 the production of galls or warts, often of a large size, 

 upon the substance of which the larvae, when hatched, 

 continue to feed until they assume the perfect state ; 

 and the remainder place their eggs in slits in the stems 

 of plants upon the leaves of which the young feed. 

 From the nature of their food, and their abode in the 

 midst of it, it will be at once evident that they have 

 little need of locomotive organs serving for its disco- 

 very. We accordingly find that the majority of the 

 hymenopterous larvae are footless grubs, of a white 

 colour, and of a fleshy substance, having the parts of 

 the mouth small, and but slightly developed, although 

 in the perfect insect the same organs attain a maxi- 

 mum degree of development. In those larva?, how- 

 ever, which are external feeders, we find the necessity 

 for locomotion causing the addition of locomotive 

 organs ; the legs in the larvae of the saw-flies varying 

 in number from six .to twenty-two. The pupae of 

 these insects are inactive, having the various limbs of 

 the perfect insect developed, but enclosed in separate 

 cases, and lying along the breast. In this respect, 

 therefore, they resemble the coleoptera, and like them 

 they are in this state either enclosed in cocoons 

 formed by the grubs previous to their transformation, 

 or are naked. The species of this order is extremely 

 numerous. They are annual insects ; the majority of 

 them pass the winter season in the form of grubs or 

 pupae, whilst others pass this period in the perfect 

 state. These, however, are but few in number, and 

 consist of femeles which have been impregnated 

 during the preceding autumn, and are destined to 

 become the foundresses of fresh colonies, upon the 

 arrival of spring. In their perfect state, they feed 

 almost exclusively upon the honey of flowers. Some, 

 indeed, have been said to feed upon other insects, but 

 these observations have been mada upon a casual 

 occurrence, or upon insects which were in the act of 

 securing the supply of food for their progeny. In 

 the tropical countries, the species attain the largest 

 size ; there, too, they appear to be the most abundant. 

 The situation of this order in the classification of 

 insects, is especially interesting. The possession of 

 a pair of robust mandibles necessarily places it 

 amongst the mandibulata or masticating insects, 

 whilst the elongated structure of the lower parts of 

 the mouth, forming a proboscis for sucking up the 

 honey of flowers, seems to unite it with the haustel- 

 lated or sucking insects. Latreille has accordingly 

 placed it between the mandibulated Neuroptera and 



