"So they are," the trainer replied, "if we were dealing with ordinary rats. But the savage rats which have developed in the trenches, creatures which are sometimes ferocious enough to kill and devour the severely wounded, are sometimes more than the snappy little fox-terriers can manage. Some of those rats have a body eight inches long from snout to root of tail and weigh over a pound. The hard wiry coat and tough skin of the Irish terrier is a good protection against the terrible down-slashing stroke of a rat's teeth. Besides which, the Irish terrier is a much more determined fighter, when aroused, and his square jaw is far more powerful than that of his black-and-white cousin." [Illustration: _Courtesy of "Illustrated London News."_ MESSAGE DOG WEARING GAS MASK. In order to escape poison fumes, dogs of the liaison have to be trained to wear masks, like soldiers.] "Why not use ferrets to drive the rats out the trenches, just as they do to drive them out of granaries and warehouses in the city?" "Too unsafe," the hunchback answered. "We can't spare men enough to send them rat-hunting with ferrets, and if we simply turned the ferrets loose, they might multiply so fast that they would kill off all the rats and then become a tenfold worse danger. A ferret is twice as long as a rat and is the most murderous creature that draws the breath of life. A plague of ferrets would be fearful. They would be worse than poison gas, which is the thing that troubles me most in the kennels here." "Why here?" asked the boy in surprise, "you're far enough in the rear to escape poison gas, surely?" "Yes, but my dogs have to work at the front," the hunchback explained, "and they need protection, just as much as the men in the fire trench. The dogs have to become accustomed to wearing gas-masks, just like soldiers. It's hard on the dogs, too, because a dog doesn't breathe much through his nose when he's running but through his mouth and so the mask has to be made in a different way. "You'd never believe the amount of trouble I have in trying to teach my dogs to keep from scratching the gas-masks off with their paws. I've got some little puppies that I keep in gas-masks all the time. I only take their alkali-soaked bonnets off at their breakfast and dinner time. They even sleep in them." "Poor little beggars!" exclaimed Horace, "and they haven't even got the satisfaction of realizing why they have to do it." "Well," said the hunchback, gravely, "I always tell them 'It's for France!' Because," he added, half-seriously, "one can never tell how much a dog understands." Horace spent the whole of his day off duty with his old friend and returned that evening to his telephone station, full of stories of the hunchback's wonderful dogs. With great gusto he recounted to his friend the veteran the story of the canine gas-masks.