The SWALLOW-TAIL BUTTERFLY is produced twice a Year. The first Brood appears in _May_, the second towards the End of _July_. Being in a Meadow near _Cookham_, in _Kent_, on the 5th Day of _August_, 1748, I observed a Female _Swallow-Tail_ hovering over certain Plants, which taking particular Notice of, I found to be the _Meadow Saxifrage_, and examining them carefully, I discovered four Eggs just laid by the _Fly_, wherewith I was highly pleased. On the 13th of the same Month these Eggs produced _Caterpillars_, of Size and Colour as expressed at Figure 1. On the 19th one of the _Caterpillars_ shifted its Skin, and appeared like Figure 2. On the 23d it changed again to the Likeness of Figure 3. On the 4th of _September_ it became like Figure 4. On the 11th of the same Month it appeared in its fifth and last Skin, which was extreamly beautiful, as expressed at Figure 5. On the 22d the _Caterpillar_ was full grown, and fixed itself in the Manner of Figure 6, in order to change into the _Chrysalis_ 7, which was produced on the 26th of _September_; in which State it remains, _January_ 20, 1748-9. I fed the _Caterpillar_ from its being first hatched with the green Leaves of the common Carrot, which it eat plentifully. This fine _Butterfly_ may be taken in the Meadows and Clover Fields about _Cookham_, near _Westram_, in _Kent_, at the Times above-mentioned. It flies so swiftly that it is in vain to follow it, you must therefore wait ’till it settles, and then, if you are near, be nimble, and you may catch it without much Difficulty. The _Flies_ are represented in the next Plate numbered the same as this. See _Reaumur_, Pl. 29. Pag. 486. Also Pl. 30. Vol. 1. Pag. 486. The Meadow Saxifrage. _Seseli pratense nostras._ Park. L. 3. CH. 3. II. CL. 1. S. _a._ 2. The BRIMSTONE-BUTTERFLY lives in the _Fly_ State all the Winter Season, for very early in the Spring you will see them in the Woods flying about and seeking out their Mates. The Food of the _Caterpillar_ is reported by Mr. _Dandridge_ to be the _Buck-Thorn_, on which he fed it ’till the Middle of _June_, when it changed to a _Chrysalis_, and the _Fly_ was bred at the Beginning of _August_. The _Caterpillars_ are rare to be met with, although the _Fly_ is common in Woods and Fields of Clover, in the Months of _August_ and _September_. The Buck-Thorn, with its Berries. _Rhamnus Catharticus._ C. B. P. CLASS II. SECT. _a._ CATERPILLARS _having little or no_ HAIR. _Fastening their ~Chrysalis~ as the last Sort, and producing_ ROUND-WINGED BUTTERFLIES. L. 3. CH. 1. I. CL. 2. S. _a._ 1.