responsible for horse stables should make sure that the manure is thrown into screened pits and sprinkled with chloride of lime at least once a week. Another method of dealing with the problem is that suggested by Professor C.F. Hodge of Clark University, Worcester, Mass. It is that of letting the flies catch themselves. He has devised a simple and inexpensive flytrap, which is easily attached to any garbage can (or to a window screen); or it may be baited with bits of fish or other food. The flies are attracted by the odors of the garbage or food bait, and when caught may be killed with boiling water. If the various suggestions are followed, even farmhouses, as experience has shown, may be rendered practically free from the filthy and dangerous house fly. V. ADDITIONAL TOPICS ON INSECTS 45. Field and library study of other insects. - (Optional.) Study as many of the following insects as time allows, consulting Sanderson's "Insect Pests of Farm, Garden, and Orchard," Hodge's "Na bug, cockroaches, plant lice, human lice (Fig. 44), bedbugs (Fig. 45), carpet beetles, lady bugs, scavenger beetles, ichneumon fly. 46. Annual loss due to insect pests of the United States.1 In no country in the world do insects impose a heavier tax on farm products than in the United States. The losses resulting from the depredations FIG. 45.-Bedbug. of insects on all the plant products of the soil, both in their growing and in their stored state, together with depredations on live stock, exceed the entire expenditures of the national government, including the pension roll and the maintenance of the army and the navy." This loss for the year 1904 was estimated at $795,100,000, and this does not include the expense involved in applying insecticides. 1 C. L. Marlitt in Year Book of United States Department of Agriculture, 1904. The figures are regarded as conservative estimates. 47. Insecticides.1 In our laboratory studies we have found that there are two kinds of insects, namely those with biting mouth parts and those with sucking mouth parts. Entirely different treatment is necessary in dealing with insect pests of these two types. Insects with biting mouth parts may usually be killed by thoroughly spraying the parts of a plant upon which they feed with a mixture made in the following proportions: Insects with sucking mouth parts, on the other hand, must be treated with a spraying mixture which will actually touch their bodies. Some of the "contact insecticides" for this purpose are whale oil soap (one pound to five gallons of water), kerosene emulsion, and “black-leaf-40." The last named is preferable for killing plant lice and it is mixed with soap as follows: 1 The authors are indebted to Professor Glenn W. Herrick of Cornell University for these formulas. 48. Study of a bird. CHAPTER II BIRDS (Optional home work.) So far as possible the following study should be made from a robin, sparrow, chicken, or other living bird, and the observations should be supplemented by an examination of stuffed specimens, charts, or pictures. A. Regions. In all animals that have internal bony skeletons as do birds, at least two of the following regions may be distinguished; namely, a head, a neck, a trunk, and a tail. B. Head. Which of the four regions named above can you distinguish in the bird that you are studying? 1. Describe the general shape of the beak (or bill), stating whether it is relatively long and slender, or short and thick. State, also, whether the tip of the beak is straight or curved. 2. On what part of the head are the eyes located? In the eyes of a bird the following parts are visible: a central pupil, and around this a colored region known as the iris. State the location and describe the color of each of these parts in the eye of the bird that you are studying. 3. In front of the eyes find two openings, the nostrils. Locate the nostrils with reference to the beak and the eyes. 4. Make a drawing twice natural size of a side view of the head to show the beak, eye, and nostril. Label each part shown. 5. Watch a chicken, canary, sparrow, or other bird while it is eating and drinking, and describe the movements that the bird makes in these acts. C. Organs of locomotion. 1. What is the position of the wings when they are not in use? 2. Note and describe the movements of the wings when the bird is flying. 3. The only part of the leg that is visible in most birds is the b. Make a drawing to show the foot and the toes with the 4. Watch several kind of birds (e.g. robins, sparrows, chickens, starlings), and state whether each of these kinds of birds walks or hops. 49. What is a bird? Birds, like fishes, frogs, and man, belong to the group of animals that have a backbone, and hence are known as vertebrates. It is never difficult, however, to distinguish birds from other vertebrates, since every bird has wings either developed or undeveloped (Fig. 46) and a covering of feathers. Birds, too, maintain a body temperature that is higher than that of any other group of animals. The temperature in man, for instance, is normally about 981° F., whereas no bird, so far as we know, has a temperature less than 100° F., and even 111° F. is known to be the temperature of some of the sparrows and warblers. Hence, we may define a bird as a warm-blooded vertebrate, having wings and a body covering of feathers and usually able to fly. Even a casual examination will show that a bird has a head, neck, and trunk, and two pairs of appendages, namely, the |