"But what is it, then?" asked Mrs. Weldon.

"A dipter, cousin, a famous dipter!" And Cousin Benedict showed a fly smaller than a bee, of a dull color, streaked with yellow on the lower part of its body.

"And this fly is not venomous?" asked Mrs. Weldon.

"No, cousin, no; at least not for man. But for animals, for antelopes, for buffaloes, even for elephants, it is another thing. Ah! adorable insect!"

"At last," asked Dick Sand, "will you tell us, Mr. Benedict, what is this fly?"

"This fly," replied the entomologist, "this fly that I hold between my fingers, this fly—it is a tsetse! It is that famous dipter that is the honor of a country, and, till now, no one has ever found a tsetse in America!"

Dick Sand did not dare to ask Cousin Benedict in what part of the world this redoubtable tsetse was only to be met. And when his companions, after this incident, had returned to their interrupted sleep, Dick Sand, in spite of the fatigue which overwhelmed him, did not close his eyes the whole night.

* * * * *

CHAPTER XVIII.

THE TERRIBLE WORD.