Have you ever tried your little chestnut at a ditch?
you wouldn't be afraid, eh ?" "Not the least in the world," said Gwendolen.

And that was true: she was never fearful in action and companionship.

"I have often taken him at some rails and a ditch too, near--" "Ah, by Jove!" said his lordship, quietly, in notation that something was happening which must break off the dialogue: and as he reined off his horse, Rex was bringing his sober hackney up to Gwendolen's side when--the hounds gave tongue, and the whole field was in motion as if the whirl of the earth were carrying it; Gwendolen along with everything else; no word of notice to Rex, who without a second thought followed too.

Could he let Gwendolen go alone?
under other circumstances he would have enjoyed the run, but he was just now perturbed by the check which had been put on the impetus to utter his love, and get utterance in return, an impetus which could not at once resolve itself into a totally different sort of chase, at least with the consciousness of being on his father's gray nag, a good horse enough in his way, but of sober years and ecclesiastical habits.
Gwendolen on her spirited little chestnut was up with the best, and felt as secure as an immortal goddess, having, if she had thought of risk, a core of confidence that no ill luck would happen to her.

But she thought of no such thing, and certainly not of any risk there might be for her cousin.