No mention has been made of the curious bazaar pictures, sold for a few pence. These cost little, but are very clever, and give free scope for originality, which is the great characteristic of the Persian artist. They consist of studies of town-life, ideal pictures of dancing-girls, and such-like. All are bold, ingenious, and original. But bazaar pictures would take a chapter to themselves, and occupy more space than can be spared.—_Chambers's Journal._ HOW INSECTS BREATHE. BY THEODORE WOOD. Perhaps in the entire range of insect anatomy there is no point more truly marvellous than the manner in which the respiratory system is modified, in order to suit it to the peculiar requirements of its owners. In many ways the structure of the insects is wonderful enough. They are gifted with muscles of extraordinary strength, and are yet destitute of bones to which those muscles can be attached; they possess a circulatory system, and are yet without a heart; they perform acts involving the exercise of certain mental qualities, and are yet without a brain. But, more remarkable still, they breathe atmospheric air without the aid of lungs. And this for a very good reason. It can be neither too often nor too strongly insisted upon that, throughout animated nature, Structure is in all cases subservient to Habit. If in any animal we find some singular development in bodily form, we may be quite sure that there is a peculiarity in the life-history which renders such development of particular service, and so may often gain very complete information with regard to the habits by a mere glance at external characteristics. If, for example, the general shape is cylindrical, the toes webbed, and the hair set closely against the body, we may safely conclude that the animal is one intended for a life in the water. If the form is conical, the limbs short, and the claws large and strong, that it is one which burrows in the earth. If the jaws are large and massive, the teeth long and sharply pointed, and the muscular power is concentrated principally into the fore-parts of the body, that it is a beast of prey. And so on with minor details.