“Not half-way up yet,” panted Jack.

“Take it coolly, men, or our hands will be all of a tremble, so that we can’t shoot straight.”

There was no need to advise an impossibility, for no one could have taken it coolly. The blocks of stone, the tangled creepers, and higher up the dense undergrowth, made it a slow, laborious task; but at last the huge trees of the upper slope were reached, and the work promised to be lighter.

The doctor made a sign, and they both sat down to rest for a few minutes, the men who came on smilingly following suit; but all at once a peculiarly hoarse cooing sound arose from not far away among the trees, and all the fatigue passed away as if by magic.

“Pigeons!” whispered the doctor excitedly. “Hark! more of them! They must be the big fruit birds, Jack, and we must have a pair or two of these. When you’re ready we’ll go on.”

“I’m ready,” whispered Jack.

“Then we’ll go abreast. Don’t you study me. Keep your eyes open, and the first moment you have a good chance you fire. Get one with each barrel if you can.”

Jack nodded, and directly after they advanced among the trees, with Ned about a couple of yards behind, carrying a second gun for whichever needed it.

These were exciting moments, more exciting than they knew of, as they crept forward among the huge trunks, and gazing upward among the branches, expecting moment by moment to catch sight of the flock of great fruit-pigeons, whose cooing kept stopping and commencing again.

It had sounded to be so close that they felt puzzled, and wondered whether they had passed them, for the doctor argued that if they had taken fright the rustle of their wings would have been heard among the branches.