"No," replied the doctor. "Their origin is rather curious. Sometimes, in the wet season, torrents rush down from the mountains to the sea, and the fresh water kills the polypus which makes the coral, and so stops the formation of it just there, and makes an opening. This theory is confirmed by the fact that all such passages through the reefs are immediately opposite valleys." "The town looks like a large fortification; I suppose the dwelling- houses are behind the walls." "No, those are the houses; and what look from here like loopholes are the windows. The place is worth looking over, though you won't have much time for that, I expect, nor yet for boating amongst the curious coral caves, or looking at the queer creatures which serve for fish and haunt them, until you have chawed up the Hadendowas and got Osman Digna in a cage." "Not then, I hope," said one of the seniors of the group. "I hope they will send us across to Berber, when Osman's forces are swept from the path." "I doubt if they will," replied the doctor, shaking his head. "It will be frightfully hot in a couple of months." "It is the only way to save Gordon." "I fear you are right, but I hope not. But here is a boat coming off to us." It was a man-of-war's boat dashing along with the smart, lively stroke which can never be mistaken. It was alongside presently, and almost the moment it touched, the naval officer they had seen in the stern sheets stood on the quarter-deck; a harlequin could not have done it more quickly. "It is a mistake your coming in here, sir," he said to the commanding officer; "you are to go to Trinkitat." So the chance of closely investigating a coral town, and seeing how closely or otherwise it resembled a similar sort of colony in an extravaganza, was lost for the present for the First Battalion of the Blankshire, who growled. And yet, oh fortunate ones! If they but knew it, they gained two more comfortable meals, and one comfortable night's lodging, by having to go on. For they did not anchor in Trinkitat harbour till it was too late to land that night. The delay caused a last rise to be taken out of poor Green, or rather a final allusion to a long-standing one. When the battalion got its route for the Soudan, the lad was as keen to see active service as any one of them, and it was a severe shock to him when one of the most mischievous of his brother officers pretended to discover that one of his legs was crooked, which would incapacitate him, he feared, from marching across the desert. "You would knock up in an hour's march, and have to be carried, you know," said the tormentor; "it would never do." "I am sure my legs seem to me all right," urged poor Green. "Well, of course, I may be quite in error," candidly admitted the other. "We will ask a doctor." So Doctor MacBean was called in, and he made an examination of the accused limb.