Latreille to the primitive wingless insects known as springtails and bristletails.
Lubbock (Lord Avebury) separated the springtails as a distinct order, the Collembola, and by many students this separation has been maintained.
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.
Most springtails are without air-tubes, and breathe through the general cuticle of the body.
In many genera of springtails a curious post-antennal organ, consisting of sensory structures (often complex in form) surrounded by a firm ring, is to be noticed on the cuticle of the head between the eyes and the feelers.