Notwithstanding its abundance and its successive broods its life-history is none too completely worked out. There is still opportunity for careful observations upon the way in which it passes the winter in various parts of its range. While in the South it apparently hibernates as an adult, this fact is not certain in the more northern localities. Notwithstanding its diminutive size this butterfly has been known to swarm in such enormous numbers as to seem a veritable cloud. The most notable record of this has been quoted by Scudder in connection with a swarm that invaded the Bermuda Islands, in 1874, on the first day of October. It was described in these words: "Early in the morning several persons living on the north side of the main island perceived, as they thought, a cloud coming over from the northwest, which drew nearer and nearer to the shore, on reaching which it divided into two parts, one of which went eastward and the other westward, gradually falling upon the land. They were not long in ascertaining that what they had taken for a cloud was an immense concourse of small yellow butterflies, which flitted about all the open grassy patches in a lazy manner, as if fatigued after their long voyage over the deep. Fishermen out near the reefs, some few miles to the north of the islands very early that morning, stated that numbers of these insects fell upon their boats, literally covering them." As is the case with so many of the related yellow butterflies there is an albino variety of this species. It has been given the variety name _alba_ although it is really a pale yellow rather than a true albino form. =The Dainty Sulphur= _Nathalis iole_ While the Little Sulphur butterfly seems about as delicate a creature as one could ask to see, it loses that distinction when it is compared with the still smaller Dainty Sulphur. The latter expands scarcely an inch when its wings are stretched apart, and its slender body and antennae help to give the suggestion of extreme delicacy. There is more marking of black upon the sulphur-yellow wings than is the case with the larger form, the upper portion of the front wings showing only a broad yellow band upon a background of darker color. The under wings are nearly all yellow. _Synopsis of the Yellows_ _Brimstone_ or _Cloudless Sulphur_ (_Callidryas eubule_ or _Catopsilia eubule_). Expanse 2 1/2 inches. Upper surface of male clear, light, sulphur yellow. Female with a brown spot in front of middle of each front wing and a narrow brown margin on all the wings. Under surface deeper yellow with sparsely scattered brownish dots. _Red-barred Sulphur_ (_Callidryas philea_ or _Catopsilia philea_). Expanse 3 inches. Easily known by the reddish orange bars on the sulphur-yellow wings. _Large Orange Sulphur_ (_Callidryas agarithe_ or _Catopsilia agarithe_). Expanse 2 1/2 inches. Distinguished at once by its uniform orange-yellow color.