SOME OTHER FLIES 23 



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 pupae of 

 many of these species are said " to be found in the 

 soil," and some, if not all the larvae, are predaceous, 

 attacking worms and underground larvae 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 Hematopota com- 

 prises 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 



