"Oh, I am sure that is it!" called out Mary Avon quite eagerly. She did not care how she destroyed the Laird’s convictions about the value of historical evidence. "That is an explanation of the whole thing." At this, our young Doctor—-who had been professing to treat this matter seriously merely as a joke—quickly lowered his eyes. He scarcely ever looked Mary Avon in the face when she spoke to him, or when he had to speak to her. And a little bit of shy embarrassment in his manner towards her—perceivable only at times—was all the more singular in a man who was shrewd and hard-headed enough, who had knocked about the world and seen many persons and things, and who had a fair amount of unassuming self-confidence, mingled with a vein of sly and reticent humour. He talked freely enough when he was addressing our admiral-in-chief. He was not afraid to meet _her_ eyes. Indeed, they were so familiar friends that she called him by his Christian name—a practice which in general she detested. But she would as soon have thought of applying "Mr." to one of her own boys at Epsom College as to Angus Sutherland. "Well, you know, Angus," says she pleasantly, "you have definitely promised to go up to the Outer Hebrides with us, and back. The longer the calms last, the longer we shall have you. So we shall gladly put up with the fine weather." "It is very kind of you to say so; but I have already had such a long holiday——" "Oh!" said Mary Avon, with her eyes full of wonder and indignation. She was too surprised to say any more. She only stared at him. She knew he had been working night and day in Edinburgh. "I mean," said he hastily, and looking down, "I have been away so long from London. Indeed, I was getting rather anxious about my next month’s number; but luckily, just before I left Edinburgh, a kind friend sent me a most valuable paper, so I am quite at ease again. Would you like to read it, sir? It is set up in type." He took the sheets from his pocket, and handed them to the Laird. Denny-mains looked at the title. It was _On the Radiolarians of the Coal Measures_, and it was the production of a well-known professor. The Laird handed back the paper without opening it. "No, thank you," said he, with some dignity. "If I wished to be instructed, I would like a safer guide than that man." We looked with dismay on this dangerous thing that had been brought on board: might it not explode and blow up the ship? "Why," said our Doctor, in unaffected wonder, and entirely mistaking the Laird’s exclamation, "he is a perfect master of his subject." "There is a great deal too much speculation nowadays on these matters, and parteecularly among the younger men," remarked the Laird severely. And he looked at Angus Sutherland. "I suppose now ye are well acquainted with the _Vestiges of Creation_?" "I have heard of the book," said Brose—regretfully confessing his ignorance, "but I never happened to see it." The Laird’s countenance lightened.