II FLIES WITH AQUATIC LARVAE 215 



The seven pairs of ventral feet are set close to 

 the middle line, and each is fused with its fellow. 



Baron Osten Sacken 1 has shown that the resem- 

 blance of the fly of Eristalis to a Bee has caused the 

 curious belief of ancient times that Hive-bees could 

 be produced by the putrefaction of dead animals, and 

 especially from the carcasses of oxen. " The original 

 cause of this delusion lies in the fact that a very 

 common fly, scientifically called Eristalis tenax (popu- 

 larly the Drone-fly), lays its eggs upon carcasses of 

 animals, that its larvae develop within the putrescent 

 mass, and finally change into a swarm of flies, which 

 in their shape, hairy clothing and colour, look exactly 

 like Bees, although they belong to a totally different 

 order of Insects. Bees belong to the order Hymenop- 

 tera, and have four wings ; the female is provided 

 with a sting at the end of the body : the fly Eristalis 

 belongs to the order Diptera, has only two wings 

 and no sting." 



Ovid, Virgil, and a crowd of less famous authors 

 vouch for the long-established belief in the miracle. 

 But the prescription for raising a swarm of Bees 

 given by Florentinus, a Byzantine author of about 

 the tenth century A.D., is more explicit and solemn 

 than any other extant. Ostcn Sacken translates his 

 instructions thus :- 



"Build a house, ten cubits high, with all the 

 sides of equal dimensions, with one door and four 



1 On the O.i -en-born Bees of the Ancients (Bugonict) and their 

 relation to Eristalis tenax , a two-winged Insect. Heidelberg, 

 1894. London : R. H. Porter. Published in shorter form in 

 Bull. Soc. Entom. Ital.^ 1893. 



