I had placed under the bell-glass at the same time four bees and as many Eristales, in order to judge of the entomological knowledge of Philanthus as exemplified in the distinction of species.

Reciprocal quarrels broke out among the heterogeneous group.

Suddenly, in the midst of the tumult, the killer is killed.

Who has struck the blow?
Certainly not the turbulent but pacific Eristales; it was one of the bees, which by chance had thrust truly in the mellay.

When and how?
I do not know.