(b) Play.—Does a puppy play in the same manner as a kitten? What differences have you noticed? Have these differences any connection with the methods of catching the prey of the adult animals? (c) Education.—Have you ever seen a puppy being taught to do anything by its mother? Write full accounts of such cases. 7. Different breeds of dogs.—Make notes of your observations of as many different breeds of dogs as possible, e.g. collies, terriers, retriever, fox-hound, pointer, spaniel, etc., and describe the resemblances and differences in size, form, habits, intelligence, etc. [Pg 250] Fig. 169.—The Cat. The external characters of the cat and dog.—The cat and the dog are so commonly kept as pets that they are perhaps more easily examined than any other animals. In addition, they are so closely related and yet exhibit so many differences that they afford a valuable exercise in the methods of comparison and contrast which are at the foundation of all successful work in Nature-Study. Several differences are at once apparent on even a casual inspection. The body of the cat (Fig. 169) is covered with soft, smooth fur, and its head is provided with long, sensitive whiskers. In both of these respects it resembles the rabbit and other mammals which are in the habit of creeping along narrow and dark passages. It is commonly said that cats can see in the dark. Although this is not altogether true—for no animal can see in total darkness—the cat’s eyes have the power of adapting themselves remarkably to the intensity of the light. In a dim light, the curtain, or iris, which surrounds the pupil (the dark, central window through which light enters the eye) is drawn back so as [Pg 251] to admit as much light as possible; whereas in a very bright light the curtain is so nearly closed that the pupil is merely a narrow, vertical slit. On the other hand, the dog (Fig. 170), which is not fond of dark passages, has its body clothed with rough hair, instead of fur; and its whiskers are not nearly so long as those of the cat. Again, although the iris of a dog’s eye alters in size to regulate the amount of light entering the eye, the pupil is always round, and the change of size is much less marked than in the cat. Another very noticeable difference is in the claws at the ends of the toes, corresponding to the nails at the ends of our own fingers and toes. In the cat these are sickle-shaped and extremely sharp, and are kept drawn completely back into sheaths when they are not required. The dog’s claws are blunt, and cannot be retracted. Both the dog and the cat rest the weight of the body upon the toes—not upon the sole of the foot—when walking or running. Fig. 170.—Foxhound.