The marked characteristic that gives these little animals their name is the pockets or cheek pouches. These are external openings outside of the mouth and are lined with a furry skin. They are ample in size and the two will hold, in some instances, a heaping tablespoonful of grain. “The filling is done so rapidly that, where a hard grain like wheat is used, a continuous rattling sound is made. The ejecting of the grain from the pockets is aided by a forward, squeezing motion of the fore feet, each foot making two or three quick forward passes. Some of the species seem to thrive in captivity, and after a few days do not fill their pouches, apparently having learned that it is a useless labor. When obtainable, their natural food consists of various plant seeds, but when in the neighborhood of cultivated fields and the vicinity of houses, they feed also upon grain and the vegetable waste from camps and houses. Mr. F. Stephens says that some of the species, whose habits he has studied, will eat about a heaping tablespoonful each of wheat or barley in twenty-four hours and one or two square inches of beet or cabbage leaves.” As they are often found in regions practically devoid of water, a large part of the year, it is highly probable that they obtain the necessary moisture from succulent leaves. In captivity they drink but little water. Mr. Stephens writes of one that he trapped that was evidently very hungry. Placing it in a cage he gave it grain. He says: “It was amusing to see the eagerness with which it immediately went to filling its pockets. It stuffed them so full that it must have been positively painful, and then it would not stop to eat, but hunted about for some exit; not finding one, it ejected the contents of its pockets in a corner out of the firelight and went back for more. This time it ate a little, but soon gathered the remainder and deposited it with the first. After eating a little more, it refilled its pockets and hunted about for a better place to make a cache, seeming to think its first choice insecure. These actions plainly show that they are in the habit of storing away their supplies.” In some fields where they are common it is said that more than a pint of grain is ploughed up in a single cache. The elongated hind legs, well pictured in our illustration, give these rats a wonderful power of locomotion. As they leap rather than run, they are often called Kangaroo Rats. Mr. Woodruff states that the specimen, which we have used, when trying to escape started with short leaps, but as it gained headway the spans were about four feet in length and at the highest point about eighteen inches from the ground. He found them quite common in the vicinity of San Diego, California. They are nocturnal in their habits, seeking their food through the twilight and night hours, and resting during the day in their burrows or in shaded places near the openings to them.