The small family of the _Stratiomyidæ_ contains a few fairly common species called soldier-flies; these are interesting as linking _Orthorrhapha_ with _Cyclorrhapha_; their larvæ are some aquatic (the star-tailed maggots), others terrestrial, and some have hard shell-like skins; but they are not so curiously like a creeping marine limpet as are those belonging to the genus _Microdon_ (of the _Syrphidæ_), which are rare and wonderful dwellers in ants' nests. There is a curiously shaped race of parasitic flies which cling to the host like a louse, called _Hippoboscidæ_; these have more than the usual provision of claws to their feet, both in the number (normally two) and size of the claws. The forest or spider-fly attaches itself to some part of the body out of reach of the horse's tongue. The ked, tick, or sheep louse-fly has a similar mode of life, and, after selecting its host, it becomes wingless. These flies, strange to say, nurse and nourish their larvæ within the oviduct, and, when one might think that they were laying their eggs, they are depositing pupæ or larvæ just ready to pupate. There are some species of the family of the louse-flies which infest birds. The true gad-flies of the family of _Tabanida_ were, and sometimes still are called "blinden breeze-flies," and sometimes dun-flies; by a very easy mistake the countryman's word "blinden" (blind) has got changed by authors in books to "blinding," which is nonsense, and misses a wonderful instance of old-folk knowledge; the females are amongst the most inveterate blood-sucking flies, but the males are mere idle loiterers in summer sunshine on flowers; the eggs are laid on herbage in moist situations; the maggots and pupæ of many of these species are said "to be found in the soil," and some, if not all the larvæ, are predaceous, attacking worms and underground larvæ of various insects. They are more or less midsummer flies and are single-brooded. There are several largeish species (of the genera _Tabanus_ and _Therioplectes_) found in Great Britain, and they are diversely distributed, being respectively woodland, moorland, lowland, and highland inhabitants. The great ox-gad-fly is as large as a bumble-bee, though more long than broad in body, but the term gad-fly is often wrongly given to the worble-fly, which is really more bee-like, being furry and rounder in body. The genus _Hæmatopota_ comprises three smaller sized extra vicious blood suckers, _H. pluvialis_, rather common, _H. italica_, very local, and _H. crassicornis_, darker in colour and with spotted and dark tinted wings. Several of the large gad-flies have dull-tinted wings. They have large, shallow, brightly shining and curiously banded compound eyes, but no "ocelli"; they all seem to be at least semi-blind, and the females are rather sluggish, except between the hours of 11 a.m. and 5 p.m. in bright midsummer sunshine. The females hunt entirely by scent and are