The adult caterpillar does not differ in marking to any considerable extent from the preceding stages. The first and last stripes do not appear larger than the intermediate ones, as the latter now increase in size. Many specimens were entirely without red spots; in others they were present, but were small and inconspicuous, whilst in others again there were two spots, one above the other, of a vivid ferruginous red, these coalescing in some cases, and thus forming one spot of a considerable size. I have never seen these spots formed into a regular, linear, coloured border to the white oblique stripes--as occasionally happens in _Tiliæ_--either in living specimens, blown larvæ, or in figures. SMERINTHUS OCELLATUS, LINN. The green eggs much resemble those of _Populi_, as also do the newly hatched caterpillars, which, as in the case of this last species, are entirely without markings. As with _Populi_, the markings are formed in the course of the first stage, and are distinctly visible before the first moult. The long caudal horn is of a red colour. After two to three days the caterpillars moult, their length then being one centimeter; the seven beautiful oblique white stripes, and the fine white subdorsal line, are more strongly pronounced, the latter becoming broader in front. They differ from _Populi_ in having the oblique stripes united in the dorsal line. The second moult occurs after another three days, and brings no important change; only the fine subdorsal line becoming somewhat fainter. Neither is the third moult, which takes place four days later, associated with the appearance of any essentially new character. The oblique stripes remain as before, but their upper portions now stand on a somewhat darker green ground-colour, whilst the subdorsal line vanishes, leaving distinct traces only on the three or four front segments. The fourth moult follows after a period of seven days, and my bred larvæ underwent scarcely any alteration in marking. Only small differences in coloration became perceptible in the head and horn, these changing to bluish. Specimens occur, although but rarely, which show in this last stage red spots in the vicinity of the oblique stripes, just in the same manner as with _Populi_, in which species, however, they occur more commonly. I only once found an adult larva of _Ocellatus_ possessing reddish-brown spots above and below the oblique stripes,[99] exactly as in one of the specimens figured by Rösel.[100] In this stage also there remains almost always on the three to six front segments, a more or less distinct residue of the subdorsal, which extends backwards from the head as a whitish line intersecting the foremost oblique stripes. (Fig. 70, Pl. VII.) RESULTS OF THE DEVELOPMENTAL HISTORY OF SMERINTHUS TILIÆ, POPULI AND OCELLATUS.