16 NATURAL BISTORT. 



little more than a week the larvae are hatched, and they feed upon decomposing vegetable 

 matters which they meet with underground. They have, besides the three pairs of horny thoracic 

 feet, eight pairs of fleshy pro-legs on the following abdominal segments, and from the last 

 segment the larvae can protrude four short tubes from which a white fluid exudes. The 

 larva is full grown in about a month, and then goes deeper in the earth, where it forms 

 a small chamber, and remains there for a time awaiting its change to the pupa state ; and 

 the pupa stays in the same cavity for about a fortnight, and then makes its way to the 

 surface in order to give birth to the imago. The average tima required for this development 

 is about nine weeks, and there are thus two broods in the course of the year, the progeny of 

 the second brood surviving the ensuing winter either in the larva or the pupa state. 



Another curious genus of this family is Bittacus, the spacies of which have very long bodies and 

 very long legs, and thus closely resemble the common two-winged flies vulgarly known as " Daddy 

 Long-legs " (Tipula), in everything but their possession of four wings. The tibise of these insects have 

 very long spurs at their apex, and the tarsi have only a single claw ; the beak is shorter and the wings 

 longer than in Panorpa. The genus includes several species which are chiefly inhabitants of warm 

 climates. Bittacus tipularius is the most abundant of the two species found in Europe, and it is con- 

 fined to the southern parts of the Continent. This insect is about an inch long to the tips of the closed 

 wings. It is of a reddish-yellow colour, with a great part of the thorax and the tips of the tibise and the 

 tarsi brownish. The wings are yellowish without any spots. It is a somewhat sluggish insect, flying 

 slowly and waveringly in the twilight. The Bittaci are, nevertheless, as predaceous in their habits as 

 their more active relatives, the Scorpion-flies ; but instead of going in pursuit of their prey, they adopt 

 the lazier method of hanging themselves up to a twig by their fore feet, and seizing with their other 

 long legs any unfortunate flying insect that comes within i*each. Curiously enough, the pairing of these 

 insects takes place when they are suspended as above described, and, as a general rule, the pair 

 are engaged in devouring some small insect which they hold between them with their disengaged feet. 

 This remarkable habit is not altogether peculiar to the Bittaci, the females of several predaceous 

 flies being always engaged in sucking some prey during the time of pairing, the reason being, 

 no doubt in all cases, that if the male ventured to pay any attention to his partner while her 

 mouth was disengaged he would himself fall a victim to his own temerity and her voracity. 



Besides these amply-winged forms we have to refer to the Panorpidse some very curious little 

 creatures forming the genus Boreus, in which the wings are useless for flight, quite rudimentary 



in the females, longer and claw-like in the males. These insects 

 have the beak long, the antennae almost as long as the body, no 

 ocelli, and two claws on the tarsi. The female has a projecting 

 ovipositor. To make up for their want of wings these insects 

 possess a considerable power of leaping; in fact, the common 

 European species was described by one of the older entomologists 

 as a cricket on this account. This common species, which occurs, 

 although not abundantly, in Britain, is called Boreus Memalis, 

 both its names referring to its being peculiarly a northern and 

 BOREUS HIEMALIS, MALE. winter insect. It does not exceed a sixth of an inch in length, 



and is of a metallic green colour, with the beak, antennae, legs, 



rudimentary wings, and ovipositor, rusty red. From October to March is the season at which this 

 curious little creature is most commonly met with. It is found on the ground among fallen leaves, 

 or upon the snow, and is even met with on the ice of glaciers. The larva lives in moss, and buries 

 itself in dry ground when about to change to the pupa state. Both larva and pupa much resemble 

 those of the Scorpion-fly. Several other species are known, especially in North America, and all 

 have the same habits. 



SUB-ORDER II. TRICHOPTERA. 



The members of this group are the insects commonly known as Caddis Flies, and we have 

 retained them as belonging to the Neuroptera, although some entomologists are inclined to rank 

 them as a distinct order of insects. This, indeed, was done many years ago by Kirby, and he was 



