There is much to be said in favour of the view entertained by some entomologists that the structural and developmental characteristics of may-flies are sufficiently peculiar to warrant the formation for them of a special order of insects, for which the names Agnatha, Plectoptera and Ephemeroptera have been proposed.
This minuter study had two origins, one in the researches of the medical anatomists, such as Fabricius (1537-1619), Severinus (1580-1656), Harvey (1578-1657), and Tyson (1649-1708), the other in the careful work of the entomologists and first microscopists, such as Malpighi (1628-1694), Swammerdam (1637-1680), and Hook (1635-1702).
Before the year 1899 mosquitoes had never been collected systematically, and had received little notice from entomologists, so that but few genera and comparatively few species were known.
Erichson (1839) and united with the Orthoptera, with which order some entomologists still associate them under the name of " Pseudoneuroptera."
Such obvious features as the number of segments in the foot and the shape of the feeler were used by the early entomologists for distinguishing the great groups of beetles.