"Now, whenever you don't bring your work, fairly close to these limits you'll know that you're overdoing the training," Dr. Bentley explained. "If you overdo on training then you injure the chances of the men of your squad. The wise trainer keeps within limits. Keep within such limits, and you'll find that, bit by bit, your men can endure more and more, and still pass satisfactorily as to diminishing heart speed after stopping grilling." "It's mighty good of you to explain all this to us, sir," Dick protested, gratefully. "Not in the least," replied Dr. Bentley. "You may recall the fact that I'm medical examiner to the High School Athletic Association." "And I also recall, sir," Prescott rejoined, "that for your work with the high school athletes you accept a salary of only one dollar a year, in place of the hundred dollars that the Athletic Association offered." "Well, if I cut prices in selected instances, that's my own affair, isn't it?" smiled the physician. "Now, we'll go on with the training work," Dick soon announced, stepping forward. "Reade! Darrin!" So the work went on, though it was not quite so grilling after that. The girls looked on with interest, at first, but there was no contest in hand---nothing for any "side" to win, so presently the high school girls found the spectacle less interesting. Tom, standing by, mopping his face, turned to see that Miss Marshall, her red parasol resting over one shoulder, had strolled away. "That was kind of Clara," laughed Tom. "What was?" inquired Belle. "To take that red sunshade further off. It made me perspire to look at it." "Red silk shuts out some of the worst rays of the sun," Laura explained wisely. "Does it?" asked Tom. "I know there must be some excuse for carrying a red sunshade." Then suddenly he colored, remarking: "That wasn't very gallant of me, but I didn't mean it quite the way it sounds." "And a red parasol helps throw a little tinge of color over a face that hasn't any too much color of its own," added Susie. "Clara is always more or less pale in summer." "She might be a lot more pale if any of those wild cattle were to roam back this way," smiled Dr. Bentley. Hardly had he uttered the words when, from the edge of the woods, there came a piercing scream, followed by a deep, bass bellow that seemed to shake the ground. All hands turned instantly, to see Clara running frantically, waving the parasol in her fright, while not very far behind her charged a bull, its head lowered. "Drop your parasol!" cried Greg. "Throw it away." "Then turn and run in another direction!" shouted Darrin. Neither Dr. Bentley nor Dick Prescott uttered a word. They had no advice ready at the instant, but turned and ran toward the imperiled girl as fast as they could go. Unused to such exercise, Dr. Bentley, who got the first start, was quickly panting and red of face. By him like a streak shot Dick Prescott, running with the speed of the sprinter.