Rearing butterflies from the egg is much practised, and is a very excellent way. One not only obtains specimens in fine condition, but gains knowledge of the early stages at the same time. The eggs of most of the Whites, the Orange-tip, the Brimstone, and some others are not difficult to obtain, but searching the food-plants for the eggs of many of the butterflies is tiresome work, and not altogether remunerative. Females may be watched when engaged in egg-laying, and having marked the spot, step in when she has left and rob the "nest." The best plan is to capture a few females and enclose them in roomy, wide-mouthed bottles, or a gauze cage, putting in with them a sprig or two of the food-plant placed in a holder containing water. The mouth of the bottle should be covered with gauze or leno, and a bit of moistened sugar put on the top outside. Either bottle or cage must be stood in the sunshine, but it must be remembered that the butterflies require plenty of air as well as sunshine, and that they can have too much of the latter. PART II. DESCRIPTIONS OF SPECIES. The Swallow-tail (_Papilio machaon_). The Swallow-tail butterfly is the only British member of the extensive and universally distributed sub-family Papilioninæ, which includes some of the largest as well as the most handsome kinds of butterfly. Our species has yellow wings ornamented with black, blue, and red, and is an exceedingly attractive insect. The black markings are chiefly a large patch at the base of the fore wings, this is powdered with yellow scales; a band, also powdered with yellow, runs along the outer or hind portion of all the wings. There are also three black spots on the front or costal margin, and the veins are black. The bands vary in width, and that on the hind wings is usually clouded more or less with blue. At the lower angle of the hind wings there is a somewhat round patch of red, and occasionally there are splashes of red on the yellow crescents beyond the band. The male and female are shown on Plate 2. The eggs are laid on leaflets of the milk parsley (_Peucedanum palustre_), which in the fenny home of the butterfly is perhaps the chief food-plant of the caterpillar. This is one of the few eggs of British butterflies that I have not seen. Buckler says that it is globular in shape, of good size, greenish yellow in colour when first laid, quickly turning to green, and afterwards becoming purplish.