thickly with white dust.

"All ab-oa-rd!"

The conductor's sonorous voice echoed down the train, and with a few mighty puffs from the laboring engine, the wheels once more began to revolve. The porter, clutching a tip in his fingers, leaped back on to his car. All the time they had been waiting in the station the locomotive had been impatiently blowing off steam, and emitting great clouds of black smoke, as though in a desperate hurry to get away from inhospitable-looking Maguez. It now lost no time in getting into motion. As the cars began to roll by, Jack gave a sudden shout.

"Ralph! The-the professor! We've forgotten him!"

"Good gracious, yes! What could we have been thinking of! We are getting as absentminded as he is. Here, stop the train! Hey, I say, we——"

But before the shouts had done resounding, a tall, spare man of middle age stepped out on the platform of one of the front coaches, and after gazing about him abstractedly for a few seconds, swung himself off, landing unsteadily on a pair of long, slender legs. So great was the shock of the professor's landing that his huge spectacles were jerked off his prominent nose, and he had all he could do to retain a hold on a large volume which he held tightly clasped under his left arm.

The boys hurried to pick up the professor's spectacles and hand them to him.

"We almost lost you, professor!" exclaimed Ralph.

"Ah, boys, I was immersed in the classics—'The Defense of Socrates,' and——"

"Why, Professor Wintergreen, where is your suitcase?" exclaimed Jack suddenly. "See—the train is moving, and——"

"Shades of Grecian Plato!" shouted the professor, glancing about him wildly. "I've forgotten it! Stop! I must get it back! I——"

He made a sudden dash for the train, which was now moving so swiftly that it was manifestly impossible that he could board it in safety. The boys both pulled him back, despite his struggles.

Just then, the car which the boys had recently vacated began to glide by. A black face appeared at the window. It was the porter, and in his hand he held a large green suitcase. It was the same the professor had left behind him when he vacated the car in which they had traveled from the East, and went forward into the smoking car with his book.

"Look out!" yelled the porter, as he threw the piece of baggage out of the window. It hurtled forth with a vehemence indeed that threatened to take off the scientist's head, which it narrowly missed.

"Fo' de Lawd!" the porter shouted back, as the train gathered way. "Wha' yo all got in dat valise—bricks?"

"No, indeed, sir," retorted the professor seriously, as his suitcase went bounding over the platform, which was formed of sun-baked earth. "I have books. The idea of such a question. Why should I want to carry bricks about with me, although the ancient Egyptians——"

By this time the porter was far out of hearing, and the last car of the train had whizzed by. Before the professor could conclude his speech, the suitcase—as if to prove his contention as to its contents by actual proof—burst open, and out rolled several massive volumes. The few loungers, who had gathered to watch the train come in, set up a roar of laughter as the professor—his coat flaps flying out behind him like the tail of some strange bird—darted after his beloved volumes.

"That's what you might call a circulating library!" grinned Jack, as the books bounded about with the impetus of their fall.

"I thought it was a Carnegie Car, you see——" began Ralph, when a sudden shout checked him. He glanced up in the direction from which it had come. A dust-covered buckboard, in which sat a tall, bronzed man in plainsman's clothes, was dashing toward them. The two buckskin ponies which drew it were being urged to their utmost speed by the driver, to whom Jack Merrill was already waving his hand and shouting:

"Hello, dad!"

In the meantime the professor was groping about on the platform, picking up his scattered treasures, and all the time commenting loudly to himself on his misfortune.

"Dear, dear!" he exclaimed, picking up one bulky volume and examining it with solicitude. "Here's a corner broken off Professor Willikin Williboice's 'The Desert Dwellers of New Mexico, With Some Account of the Horn Toad Eaters of the Region.' And what have we here? Eheu! the monumental work of Professor Simeon Sandburr, on the 'Fur-Bearing Pollywog of the South Polar Regions,' is——"

"Slightly damaged about the back!" broke in a hearty voice behind him. "But never mind, professor; the pollywogs will grow up into frogs yet, never fear. We'll soon have those volumes mended; and now let me introduce myself, as my son Jack seems unable to do so. My name is Jefferson Merrill, the owner of Agua Caliente Ranch."

"Delighted to meet you, sir," said the professor. "Proud to encounter a man whose name is not unknown to science in connection with his efforts to uncover something of the history of the mesa dwellers of this part of the world."

"Whose relics, if my son informed me rightly in his letters from school in the East, you have come to study, professor."

"Yes, sir; thanks to your hospitality," rejoined the professor, imprisoning his recovered volumes with a click of his suitcase clasps; "it was extremely handsome of you to invite me, and——"

"Not at all, my dear sir, not at all," expostulated the rancher, a kindly smile spreading on his bronzed features. "Besides," he continued in his breezy manner, "as Latin professor at Stonefell College you will no doubt be able to give an eye to your two pupils, and keep them out of mischief better than I could." Here the professor looked doubtful. "You see, we're pretty busy now, what with cattle rustlers and——"

"Cattle rustlers, dad!" exclaimed Jack. "Hooray!"

"It's nothing to be enthusiastic over, my boy. Several of the border ranchers have suffered severely recently from their depredations."

"Have you lost any stock, dad?"

"No; so far, I have luckily escaped. But the rascals may come at any time, and it keeps me on the lookout. They are well organized, I believe, and have a stronghold somewhere back across the border. So you boys will have to depend on your own devices for amusement. But now come, don't let's stand baking here any longer. There's a long drive before us, and we had better be getting on."

"But, dad, look at all our baggage!" cried Jack, pointing to the heap of trunks the baggage car had dropped. "There'll never be room for all of us in that buckboard."

"So I guessed," smiled his father. "So I had Bud Wilson bring in two ponies for you boys to ride out on. You told me, I think, that your friend Ralph, here, could ride."

"Good for you, dad!" exclaimed Jack impulsively; "it'll be fine to get in the saddle again—and to see old Bud, too," he added.

"Who is Bud?" asked Ralph.

"You'll soon get to know him yourself," laughed Mr. Merrill. "But you boys go and get your horses. While you are gone the professor and I will try to get some of these independent gentlemen standing about to give us a hand to load the trunks on. Then we'll drive on to the ranch. You can overtake us. Eh, Professor Summerblue?"

"Wintergreen, sir," rejoined the professor in a dignified way.

"Eh—oh, I beg your pardon. I knew it was something to do with the seasons. I hope you will pardon me, Professor Spring——No, I mean Wintergreen."

"Just like dad, he never can remember a name," laughed Jack, as the two boys hastened off to find the ponies and Bud.

"Maybe he is