And though the pig of James was a good white pig, with a black patch on his right side and one little dab of yellow fur where his tail would have been if he had had one, yet, compared to the guinea-pig of Peters, he was nothing. James, however, didn't mind the loss of admiration for his pig, and he offered Peters to let the pigs live together, which would be better for both of them, because a guinea-pig is the most sociable thing in Nature, and are known well to pine, and even die, if kept in single captivity. But Peters had a secret fear that the pig of James was not sound in its health. He told me that he had made a most searching examination of James's pig, and discovered a spot of pink skin on its chest. He said it might be nothing, but, on the other hand, it might be some infectious disease. Also James's pig was inclined to go bald; so he thanked James very much, and said he thought that if the pigs saw each other through the bars from time to time it would be all they wanted to brace them up and cheer them. But he thought, upon the whole, they had better not meet.

James didn't like this. He was rather a rum chap in many ways, but very good at English grammar and chemistry; and he had invented a way of cribbing, while a master was actually in the room, that many copied afterwards. James got rather rude about the guinea-pig of Peters, and seemed to think in some way that it was the pig, and not Peters, that had decided not to live with his pig.

He said one day, when looking at the champion pig, "I suppose the little beast thinks it's too big a swell to live with my honest, short-haired pig. All the same, if they had a fight, I know which would jolly well win."

"So do I," said Peters. "If a race-horse had a fight with a cart-horse, the cart-horse would win. This is not a prize-fighting pig."

West was there and said the same. He, of course, understood all about prize-fighting, owing to his brother being winner of the 'middle-weights' at the championship of the army; and he said that if these pigs fought, the superior weight of James's pig behind the shoulder would soon settle it. Besides, of course, the other one's hair streamed all over it like a skye terrier's. You could see at a glance that it was never born to be a fighter.

"However, if you want a fight," said Peters, who was always cool and polite, owing to copying Sherlock Holmes, "if you want a fight, James, I can oblige you."

They were both fourteen-and-a-half, and James was a lot fatter, but not so tall as Peters.

"No," said James, "I don't want to fight. I didn't mean anything of the sort."

"I may be able to get you a guinea-pig like mine next holidays," said Peters; "and if I can, I will."

"I don't want it," said James. "I don't care about these guinea-pigs that look like penwipers gone mad. I'd rather have mine."

This, of course, was mean and paltry jealousy, and we rotted James till we rather got his wool off.

A week afterwards the champion pig was found dead on its back, with its paws in the air and its eyes open, but dim. They had a look of fright in them; and it was very interesting indeed, this happening to Peters, because it would be sure to show if his detective powers were really worth talking about.

Of course everybody said it must be James; and James said, and also swore, that it was not.

Peters told me privately that he was trying to keep a perfectly open mind. He said there were many difficulties in his way, because in the event of a human being dying and being found stark you always have a post-mortem, followed by an inquest; whereas with a mere guinea-pig, belonging to a boy in a school, there is not enough publicity. He said that up to a certain point publicity is good, and beyond that point it is bad. Sherlock Holmes always set his face against publicity until he'd found out the secret. Then he liked everybody to know it, though often not until the last paragraph of the story. That showed his frightful cleverness.

I said, "I suppose you will ask yourself, 'What would Holmes do if one evening, while he was sitting improving Watson, there suddenly appeared before him a boy with a dead guinea-pig?'"

And Peters said, "No. Because a guinea-pig in itself would not be enough to set the great brain of Holmes working. If there were several mysterious murders about, or if there had been some dark and deadly thing occur, and Holmes, on taking the pig into his hand and looking at it through his magnifying-glass, suddenly discovered on the pig some astounding clue to another fearful crime, then he would bring his great brain to work upon the pig; but merely as a guinea-pig suddenly found dead, it would not interest him. In my case it's different. The pig was a good deal to me; and this death will get round to the man who gave me the creature, and he'll be sure to think I've starved it, and very likely turn from me; and being my godfather, that would be jolly serious. In fact, there are several reasons why I ought to find out who has done this, if I can."

I said, "It may be Fate. It may have died naturally."

He admitted this. He said, "That's where a post-mortem would come in, if it was a human being. Of course, Holmes never did post-mortems himself, that not being his work; but I've got to make one now. It may or may not help me."

He made it, and it didn't help him. My own opinion is that he didn't much like it and hurried it a good deal. He said there was no actual sign of violence on the surface of the guinea-pig, and the organs all seemed perfectly healthy. But when I asked him what they would have looked like if they hadn't been healthy, he avoided answering, and went on that the pig's inside ought to have been sent up to Somerset House, for examination by Government officials, in a hermetically sealed bottle. Peters declared that the public has a right to demand this service for the stomachs of their old friends and relations if foul play is suspected; but not in the case of a domestic beast like a guinea-pig.

So the pig was buried, and not until then did Peters really seem to set to work. The actual horror of the death gradually wore off, and he told me that he should now seriously tackle the case.

There was a most unusual lack of clues, he said; and he pointed out that even Sherlock Holmes could do nothing much until clues began to turn up. Peters warned me against always taking it for granted that James had done it. In fact, he said it was very unlikely to have been James, just because it looked so likely.

I said, "That may be the way Sherlock Holmes talks; but it seems to me to be rather footle."

And he said, "No, Maydew; it isn't footle; it is based on a study of the law of probabilities. If you read accounts of crime, you will see that, as a rule, the person who is suspected is innocent; and the more he is suspected, the more innocent he is."

I said, "Anyway, James has changed. He's gone down four places in his class and lost his place in the second 'footer' eleven also. There's something on his mind."

"Yes," said Peters, "that's true. Everybody believes that he killed a valuable guinea-pig, and treats him accordingly. That is quite enough to send him down four places in the class; but if he had killed the