THE EMPEROR-MOTH. The best Way to be furnished with this fine _Moth_ is, to breed it from the _Caterpillar_, which may be found in its infant State during the Month of _May_; but it is most adviseable to seek for them before the 20th. The _Caterpillars_, when newly hatch’d, are sociable, and keep together for about three Weeks, after which Time they separate and are difficult to be found. The most certain Food to take them on is the _Black Thorn_, and of that such as is not of above two or three Years Growth. They are usually found on Twigs about one or two Feet from the Ground, and (as I have observed) herd in Clusters together, when they are in their first, second and third Skins.—On the 12th of _May_ 1745, I had about sixty _Caterpillars_ hatched from such Sort of Eggs as are expressed round the _Black Thorn_ in the Plate: On the 19th they appeared in their second Skin; on the 25th, in their third; on the 18th of _June_, in their fourth, and, on the 22d, in their fifth. The _Caterpillars_ grew so much in this Skin in four Days, that they were three Times as big as when full fed in their fourth Skin. On _June_ the 30th, they shifted into their sixth and last Skin; in which Skin (as well as in the former Skins) such as appear most Green are the female _Caterpillars_. On the 12th of _July_ some of them began to spin Cases, in order for their Change into the _Chrysalis_ State; and, on the 26th, the whole threescore had spun themselves up. Thus they remained throughout the Winter, and, from the 16th to the 30th of _April_ following, I had forty of the _Moths_ bred; but the Rest of the _Aurelias_ did not produce their _Moths_ till the Year following: So that about twenty of my Number were in the _Chrysalis_ State near two Years; and yet produced _Moths_ at last that were equally beautiful and large. The Female lays from 250 to 300 Eggs, in such Manner as is represented in the Plate, and these she hides in three or four different Places for the more certain Security of some of them. The Case which contains the _Chrysalis_ is well worthy Notice, being composed of a glutenous Matter fit to resist all Kinds of Weather; and, for its greater Security, that Part which I call the Mouth is doubly guarded: So that, if any Insect should chance to force the first Fence, it will there meet with a second Resistance, and that of so strong a Nature, from its particular make, that I am apt to believe few, if any, can ever enter; and thus the _Chrysalis_ is preserved in the most secure and wonderful Manner, as will be better understood by attending to the Figure represented in the Plate. The _Moth_ is very seldom taken in the Fly State. The Black Thorn. _Prunus Sylvestris._ Ger. L. 1. CH. 1. III. CL. 2. S. _a._ 3. This Plate represents the _Male_ and _Female_ of the EMPEROR-MOTH, of which I have already given an Account.