IV 
very frequent references to previous paragraphs which, to some 
readers, may appear tedious, but which I considered useful. 
Each of the chapters of the Supplement treats of a single sub- 
ject, and, by means of such references and repetitions, can be 
read and understood separately from the others. 
My first Essay (1893) merely established the identity of 
the oxen-born bee of the ancients with the fly Hristalis tenax. 
This second edition shows progress in three principal points: 
1°. It affords the proof that the processes, used by the 
ancients for what they called ,making bees* (apes facere), pre- 
posterous as they appear, are very rational processes for ob- 
taining the ,oxen-born bee* (Hristalis tenax), but by no means 
the real honey-bee (Apis mellifica). 
2°. It gives, what I believe to be a plausible explanation 
of the apparent stolidity of the ancients in producing, for 
centuries, artificial ,oxen-born bees“, without ever becoming 
aware that these so-called bees never gave them any honey 
(or any money, as the compositor made it appear in one of the 
proof-sheets). 
3°. It shows that the horse-born hornet of the ancients 
(Pressus humo bellator equus crabronis origo est, Ovid. Met. XV, 368) 
is nothing but the common parasite of the horse, the gadfly, 
or bottly (Gastrophilus equi). 
Besides the natural explanation of the cause and origin 
of a superstition which has become historical, my investigation 
of the subject offers several collateral aspects of scientific 
interest: 
1. It tells the tale of H. tena, an insect which seems to 
have been ,for man’s confusion born“, passing unknown and 
unobserved for thousands of years, and causing a great amount 
of absurdity to grow wherever it appeared. 
2. It proves, by the study of the wanderings of this insect 
over the globe, that Darwin was right when he said: ,Now 
I maintain against all the world that no man knows anything 
about the transoceanic power of migration* etc. (Life and Let- 
ters, II, p. 243, in a letter to J. D. Hooker). Comp. below, p. 32. 
