There is a proverb which may be translated as follows: “Take nest and eggs from brooding bird--no fruit is found, no song is heard.” Also in the Bible we read: “If a bird’s nest chance to be before thee in the way, in any tree or on the ground, whether they be young ones or eggs, and the dam sitting upon the young or upon the eggs, thou shalt not take the dam with the young.” We must guard the nests from evilly disposed men and from roving predatory animals as much as lies in our power. But the real problem is this: The landowner uproots bushes, fells old trees, prevents the nest building of our most useful birds and cannot give back to them what they have lost. He prevents the possibility of their collecting again and increasing, and consequently from performing their useful duties, which are continually increasing. Where, however, bushes and trees have been rooted up, new ones may be planted, and the birds encouraged to return, although we cannot replace them at once--for hundreds of years may pass before the trees grow tall enough, and we cannot wait so long. Then we try to do by artificial means what we cannot do by nature; and we must be careful to study nature in our operations or we shall not succeed. The Woodpecker, which lives in hollow trees, shows us how to build an artificial nest. Table V., Fig. 1, gives a section of the nesting-hole of a Woodpecker built by himself. Fig. 2 is a perfectly designed nest for Titmice. Fig. 3 shows the same nesting-box complete, provided with entrance hole and cover. Fig. 4 shows an open nest-box for Flycatchers and a black Redstart. The most important is that shown in 2 and 3 as it is specially arranged to suit Titmice. [Illustration] Nest-boxes, and especially their holes, should, of course, be of different sizes, according to the birds that are to inhabit them. The opening is always round, and is of varying size according to the species. Many directions as to these are given in a paper by Baron von Berlepsch, “On the Protection of Birds Generally,” published by the German Association for the Protection of the Bird World, and also by publications of the Royal Society for the Protection of Birds in Hanover Square, London. [Illustration: Nesting Boxes on Poles.] The following are some approximate measurements for nest-boxes:-- height, 11½ inches; depth from back to front, 4½ inches; diameter of round opening, 1¼ inches. For birds of the size of a Starling: For Titmice: height, 18½ inches; depth back to front, 9 inches; diameter of opening, 1¾ inches. For Green Woodpeckers: height, 19¾ inches; depth back to front, 9 inches; diameter of opening, 2⅜ inches. The measurements for the Wild Pigeon are the same as these last, except for the opening, which should be about 4½ inches wide. Flycatchers and Wagtails require a box as shown in Fig. 4. This is 9 inches high, and has an opening about 4 inches square.