14 
Heliogabalus oftentimes sent them vessels filled with frogs, 
scorpions, snakes, and other disgusting animals. Such vessels 
were sometimes filled with numerous flies, which he called tame 
bees.“ These tame bees were undoubtedly Hristalis tenax, and 
the practical joke of the Roman emperor consisted in frigh- 
tening his friends with them. 
Réaumur (Mém. vol. IV. 489) came a little later than the 
above-quoted authors, and made use of their works (Compare 
vol. I, p. 29 and vol. IV, in many passages about Vallisnieri). 
It is Réaumur who, for the first time, brought the Bugonia and 
E. tenax distinctly together. At the very beginning of the 
chapter: ,Of two-winged flies which look like bees‘, in which 
he gives the life-history of this fly, the following passage occurs: 
,such resemblances (between certain hymenoptera and diptera) 
have deceived people at a time when observations were not 
very accurate; such resemblances have made people believe 
that honey-bees, humble-bees, hornets and wasps originate in 
putrescent matter upon which those other flies occur.“ (,Ce 
sont ces mémes ressemblances qui en ont imposé dans des temps 
ou Yon n’y regardait pas d’assez prés; ce sont ces ressemblances 
qui on fait croire que les abeilles, que les bourdons, que les 
frelons et les guépes venaient de certaines matiéres pourries 
sur lesquelles on trouvait les autres mouches.*) — This is the 
explanation of the Bugonia in a nutshell. 
Réaumur’s observations on rat-tailed larvae refer to two 
genera of diptera: 
Eristalis (his mouche & forme d’abeille), represented by 
E. tenax (the carcase-born honey-bee of the ancients) and another 
species, probably FE. arbustorwm. 
Helophilus (his mouche @ forme de guépe), the carcase-born wasp 
of the ancients (Comp. Réaumur IV, p. 440 and 474). 
Besides these two forms of diptera, a third one, also de- 
scribed by Réaumur (IV, 541—551), although not produced from 
a rat-tailed larva, has been connected by the ancients with 
the Bugonia; this is our Gad-fly (Gastrophilus equi), a parasite 
of the horse, the brownish color of which probably gave rise 
