: 15 
to the belief that it was the horse-born hornet. Thus it hap- 
pened that the hornet became, in the mind of the ancients, 
always connected with the horse, just as the honey-bee with 
the ox. (1) 
But Réaumur was working at a time when a systematic 
nomenclature of Entomology was not yet introduced, and that 
prevented him from expressing his meaning with more precision, 
in other words, from naming the species which he meant. Thus 
it happened that the very important, but perhaps too concise, 
passage which I have quoted, has ever since been entirely 
overlooked, as if it had never existed. I have searched in vain 
in Kirby and Spence, in Westwood’s Introduction, (2) and in 
other entomological works for any other passage, either allu- 
ding to Réaumur, or offering an independent explanation of the 
origin of the Bugonia. (3) A full exposition of the subject 
became therefore necessary. 
(1) In Supplement V will be found a more detailed statement about 
the identification of the horse-born hornet of the ancients with the Gad-fly, 
Gastrophilus equi. In the same place I explain the error committed by several 
ancient authors in confounding this horse-born hornet with the carcase-born 
wasp (the mouche-guépe of Réaumur, our Helophilus). The former is a para- 
site of the horse, and therefore was rightly always connected with it. The 
latter (Helophilus, carcase-born wasp of the ancients) is not a parasite, and is 
not in any way particularly connected with the horse; its rat-tailed larva may 
develop in any kind of water containing decaying organic matter. 
(2) The passage in Westwood, Introd. II, p. 557: ,Many species so much 
resemble humble bees, wasps and other Diptera, that they are constantly mistaken 
for them by the inexperienced“ contains no reference whatever to the Bugonia. 
(3) Since the publication of my first paper on the Bugonia, Prof. A. Giard 
of Paris has called my attention to a recently published volume in which, for the 
first time since Réaumur, Mristalis tenax is mentioned in connexion with the 
oxen-born bees of the ancients. In the 4th volume of the ,Souvenirs Entomo- 
logiques* by J. H. FABRE (p. 260; 1891) this author, in mentioning EF. tenax, 
calls it ,the virgilian bee“ (l’abeille virgilienne), without any other comment; at 
any rate this proves that he shares my view in that matter. 
