In insects so widely separated as bristle-tails and moths this occurs occasionally.
In these forms, however, the third joint is really a complex, which in many families bears in addition a jointed bristle (arista) or style, representing the terminal joints of the primitive antenna.
Spring-tails and bristle-tails (order Aptera) of several species also frequent ants' nests.
Others again play the part of thieves in the ant society; C. Janet observed a small bristle-tail (Lepismima) to lurk beneath the heads of two Lasius workers, while one passed food to the other, in order to steal the drop of nourishment and to make off with it.
13) in the female are paired, each ovary consisting of a variable number of tubes (one in the bristle-tail Campodea and fifteen hundred in a queen termite) in which the eggs are developed.
Thysanura (Bristle-tails): with ten abdominal segments; number of abdominal appendages variable.
Strigosa, Schreb, "the bristle-pointed oat," is the origin of the Scotch oat, according to Buckman.
Brauer (1869), on account of its likeness in shape to the bristle-tail Campodea.
Macmillan & Co., Ltd.) b, bristle; cs, caudal spine; ph, pharynx; s s', the spines on the two segments of the proboscis; sg, salivary glands; st, stomach.
The bristle tails have an abdomen of eleven segments, the tenth usually carrying a pair of long many-jointed tail-feelers (cerci, fig.
Sa, Dorsal bristle of the Sch, Plates.
The larvae have a somewhat swollen abdomen, which is protected by bristle-bearing tubercles.
13, od) leads, and in some of the more primitive insects (bristle-tails, earwigs, may-flies) the two oviducts open separately direct to the exterior.
Consequently the modern order Aptera comprises only a very small proportion of Linnaeus's " Aptera " - the spring-tails and bristle-tails, wingless Hexapoda that stand evidently at a lower grade of development than the bulk of the class.
Brauer (1885), who separated the spring tails and bristle-tails as a sub-class Apterygogenea from all the other Hexapoda, these forming the sub-class Pterygogenea distributed into sixteen orders.
The effect of the study on Mr Spottiswoode's own methods was most pronounced; there is scarcely a page of his mathematical writings that does not bristle with determinants."
But the bristle-tails and springtails, which form the modern order Aptera, are all without any trace of wings, and, on account of several remarkable archaic characters which they exhibit, there is reason for believing that they are primitively wingless - that they represent an early offshoot which sprang from the ancestral stock of the Hexapoda before organs of flight had been acquired by the class.
The head of a bristle-tail carries a pair of compound eyes and a pair of elongate many-jointed feelers.
The air-tube system is developed in varying degree in different bristle-tails, the number of pairs of spiracles being three (Campodea), nine (Machilis), ten (Lepisma), or eleven (Japyx).
In the Machilidae and Lepismidae (these two families are known as the Ectotrophi) the maxillae are like those of typical biting insects, and there is a median tail-bristle in addition to the paired cerci; while in the Campodeidae and Japygidae (which form the group Entotrophi) the jaws are apparently sunk in the head, through a deep inpushing at the mouth, and there is no median tail-bristle.
Among the bristle-tails we find the genus Machilis, represented in Europe (including the Faeroe Islands) and in Chile; while Campodea lives high on the mountains and in the deepest caves.
- a, Bristle of Pionosyllis Malmgreni; b, Hook of Terebella.
- The Aptera are divided into two divergent sub-orders, theThysanura or bristle-tails, and the Collembola or springtails.
Springtails and bristle-tails live in damp concealed places - under stones or tree-bark, in moss, and in the decaying vegetable or animal matter which serves as food for most of them.
A species of bristle-tail (Machilis maritima) and quite a number of springtails haunt the sea-coast at or below high-water mark.
Broad above the base, and taper upward into a fine point; the edges are serrated; the two lower teeth are drawn out into bristle-like points.
Its inner surface is furnished with ridges beset with series of minute, bristle-like, erect, horny teeth, each of which, when strongly magnified, is seen to be formed of a column of superposed cones, hollowed out at the base and capping each other; the summit or crown of each of these cones is expanded, spatulate, hooked backwards, and often multicuspid.