fellows.
I didn't even know this camp was here."

"What do you reckon it is?" asked Dick.

"Give it up," answered Bud. "I reckon even Zip Foster couldn't make anything of this."

"Who's Zip Foster?" asked Nort.

"That's what a lot of us would give a deal to know, son," chuckled Babe, who was rapidly making a survey of the camp. "He's a secret friend of Bud's, an'——"

"Oh, cut it out!" exclaimed Bud, and even his tan did not altogether hide the blood that surged into his face.

While the two professors were conversing together in low tones, and their helpers, including two white men (evidently the Ed Newton and Silas Thorp spoken of by Professor Blair) were putting to rights the somewhat disrupted camp, Slim, the foreman, came from the tent.

"They're not much hurt," he declared. "Only flesh wounds, but they ought to be treated with some dope I've got at the ranch house. They can ride over, and I'll fix 'em up as best I can," he offered.

"You are very kind," murmured Professor Wright. "But it might be dangerous for them to do so."

"Dangerous!" exclaimed Slim.

"Yes, I mean it might inflame their wounds."

"Oh! Yes, it might," agreed the foreman after a moment of thought. "Wa'al, I can send one of the boys back for the medicine. Here they come now," he added, as, with whoops of delight at the prospect of a fight, a troop of other cowboys from the Diamond X ranch rode up. As Bud had surmised, his mother had sent them after the advance party.

"What's the row?" cried "Yellin' Kid" Watson, as he unlimbered his gun. It needed but one utterance of his to establish his nickname. He shouted almost every word he used.

"All over," said Slim, succinctly. "Don't know just what it's about, but it's all over."

The newcomers rode their horses into the camp, and Yellin' Kid, whose animal was a bit restive, nearly brought down one of the small tents. As it swayed, a flap opening because of the breaking of one of the ropes, Professor Wright sprang forward with a sharp cry.

"Don't go in there! No one must enter that tent!" sharply commanded the scientist.

"I wasn't aimin' to," remarked Yellin' Kid somewhat tartly and in rather grieved tones. "Come out of that, you soap footer!" he cried to his steed. "What do you mean, slippin' all over creation?"

He backed his animal away, but Professor Wright, summoning to his side Professor Blair, quickly fastened the tent shut again, paying no heed during this operation, to the cowboys.

"Seems mighty much afraid we'll see something we hadn't a right to," commented Bud to his cousins.

"Yes, he does act queer," agreed Dick.

"Suspicious, I call it!" whispered Nort. He was impulsive, and much more prone, than was his brother, to ascribe motives to others. "Maybe, after all, they have gold in there!" he said.

CHAPTER V

HITTING THE TRAIL

Bud Merkel shook his head as Nort Shannon offered this possible explanation of the action of Professor Wright.

"Never's been any gold found in these regions all the years I've lived here," he said.

"There's always a first time," countered Nort, while the cowboys gazed about them, talking in low voices.

"It must be something else," said Bud. "This is a prospecting bunch, it's easy to see that, but they're not after gold. These two professors are from some eastern college, I take it," he went on. "They may be after specimens of plants, or stones. Using their vacation this way. I've heard of it being done."

"That's right!" chimed in Dick. "Two of the professors from our Academy spent all one summer in the Adirondacks, getting material for a new geology book they were writing. Maybe that's what these professors are doing," he suggested.

"Then why are they keeping so blamed secret about it for?" asked Nort, impulsively. "There's no crime in getting rock specimens, or in making up a new geology, only I wouldn't want to do it," he finished with a grin. "I get enough of study all winter. We came out here to have fun!"

"And we've started in right!" declared his brother. "Fun and excitement."

"I reckon we'll have to let these fellows have their way," murmured Bud. "They aren't on our ranch, and this is a free country. They may have permission from the Double Z people to look for specimens here."

"Is this Double Z land?" asked Dick.

"Right about here is," answered Bud. "Our line runs over there, and back where we came from," and he motioned toward the ranch buildings. "Better be hitting the home trail too, soon," he commented. "It'll be dark in no time, and I'm as hungry as they make 'em!"

"You said something then!" declared Babe. "I don't see that we can do anything more here—they don't appear to want us overly much," he added.

Perhaps Professor Wright was aware that a little feeling had arisen over his hasty warning to Yellin' Kid, for he hastened toward the foreman and said:

"I shall be most grateful to you if you will send over something for the two wounded men. I don't like to let them go to your place, hurt as they are, and I don't like to deplete my force. Those rascals may return."

"That's right," agreed Slim. "Wa'al, I reckon we can accommodate you. I'll send one of the boys back with a bottle of antiseptic stuff right after grub. Wash out the wounds, pour some of this stuff on and bind 'em up. The men'll be all right. Greasers don't mind a little thing like a bullet through the arm or leg. You know 'em?"

"No, I only hired them three days ago to help with our camp outfit. Some of my men deserted, and I have reason to believe it was some of them who led the attack on us."

"Any special reason why they should shoot you up?" asked Slim. "That is if it isn't askin' a personal question," he added, mindful of the reception accorded Yellin' Kid.

"It is all due to a foolish mistake," said Professor Wright, with a quick glance at his assistant, Professor Blair. "We are here on a scientific mission, as perhaps Professor Blair told you, and a few of the deluded men I engaged to help me make some excavations imagine I am after gold. That is far from the truth, for——"

"It is far more valuable than gold!" exclaimed Professor Blair.

"Eh—well, yes, in a way," said the chief, as Bud caught a look of warning flashed at the man who had ridden for help. "But that is neither here nor there," went on Professor Wright. "The point of the matter is that I had to discharge the leader of my uneducated helpers because he persisted in trying to find out what we were after. He took some of the men with him, necessitating the hiring of others. Then the climax came this afternoon, when, unexpectedly, we were attacked. In my wanderings I had seen your ranch buildings, and I ventured to hope you would send us help when I dispatched my assistant to you."

"Wa'al, we did what we could," said Slim. "Of course you know your own business best, but I wouldn't take any chances with Greasers. They may come back, if you have any valuables here."

"We have," said Professor Wright, with a glance at the tent, the flaps of which he had tightly closed. "But I do not fancy they will again attack us soon. We wounded some of them before you came, and we shall now be on our guard. If I can have the antiseptics for those two men, I shall be grateful."