They followed the track for a considerable distance, and still it continued, till they calculated that they were at least four miles from the shore. They were struck by the evergreen appearance of the trees and the herbage generally. Some of the trees were in blossom. "Here, here," cried Willy. "Look at these red berries. They seem quite ripe, and I saw several birds perched on the tree eating them." The doctor hastened up, and nibbled one of the berries in a cautious manner, to ascertain its nature. "Ah, yes, a subacid flavour; they are wholesome, I should think. Peter, just eat a handful, and we will judge whether or not they are poisonous." "But suppose they prove the latter?" asked Peter. "Why, then you will have the honour of suffering for the benefit of science," answered the doctor, laughing. "But you need not be alarmed; I will set you an example." The doctor tasted another berry. Peter then ate nearly a handful, acknowledging that, though the flavour was pleasant, they were very acid. "We will mark the spot," said the doctor, "and on our way back carry a load down to Mrs Rumbelow to preserve." "But where is the sugar to come from, doctor?" asked Willy; "we have but a small stock remaining." "Perhaps we may find some on our journey," said the doctor. "Numerous roots possess saccharine qualities, and from the flavour of one I dug up just now I have hopes that we may manufacture sugar from it. At all events, it will form a valuable addition to our daily fare. What do you think of this?" The doctor produced a good-sized root, which resembled, on being cut open, something between a potato and a turnip, but of rather a drier character than either. "This will serve us for bread, if we cannot find anything better;" and the doctor tasted it two or three times. "Yes, there is an abundance of saccharine in it," he observed, "and I have little doubt also that we can manufacture beer from it, which will suit the tastes of the men better than cold water, and serve instead of tea for all of us when our store runs short. If we find nothing else during our expedition, we should be well satisfied. But remember that, however insignificant a plant may look, we should examine it thoroughly to ascertain its character." "I have seen plenty of those leaves at no great distance from the village," said Peter Patch; "but I had no idea that there were roots under them." "Ah! so much the better; we shall have a supply of food at our doors, and when we return you shall go out and dig them up, Peter," said the doctor, who perhaps, rather doubted the correctness of the midshipman's assertion.