Studies in the Theory of Descent, Volume I

98

The caterpillar is thus figured by Rösel.

99

[In 1879 Mr. E. Boscher found about thirty full-grown caterpillars of this species in the neighbourhood of Twickenham, ten to twelve of which were feeding on Salix viminalis, and the remainder, from a locality not far distant, on Salix triandra. The whole of the specimens taken on the plant first named, had the red-brown spots above and below the oblique stripes more or less completely developed, as I myself had an opportunity of observing. In these spotted specimens the ground-colour was bright yellowish-green, and in the others this colour was dull whitish-green above, passing into bluish-green below. Should these observations receive wider confirmation, it would be fair to conclude that this species is now in two states of phyletic development, the more advanced stage being represented by the brighter spotted variety. (See also Proc. Ent. Soc. 1879, p. xliv.). Mr. Peter Cameron has recently suggested (Trans. Ent. Soc. 1880, p. 69) that the reddish-brown spots on the Smerinthus caterpillars may serve for purposes of disguise, as they closely resemble, both in colour and form, certain galls (Phytoptus) of the food-plants of these species. If this view be admitted, these spots must be considered as a new character, now being developed by natural selection. The variation in the ground-colour of the two forms of S. Ocellatus may possibly be phytophagic, but this can only be decisively settled by a series of carefully conducted experiments. R.M.]

100

“Insekten-Belustigungen,” Suppl. Pl. 38, Fig. 40.

101

“Catalogue of Lepidop.” British Museum. [Butler divides the subfamily Smerinthinæ into 17 genera, containing 79 species, viz. Metamimas, 2; Mimas, 4; Polyptychus, 7; Lophostethus, 1; Sphingonæpiopsis, 1; Langia, 2; Triptogon, 23; Laothoë, 2; Cressonia, 3; Paonias, 2; Calasymbolus, 5; Smerinthus, 5; Pseudosmerinthus, 2; Daphnusa, 4; Leucophlebia, 5; Basiana, 10; Cæquosa, 1. R.M.]

102

“Cabinet Orient. Entom.,” p. 13, Pl. VI., Fig. 2. [Butler places this species doubtfully among the Sphinginæ. R.M.]

103

“Catalogue of the Lepidop. Insects of the E.I. Co.,” by Horsfield and Moore. Pl. VIII., Fig. 6.

104

[The larvæ of four other species of this subfamily have since been made known through Mr. Butler’s figures. Smerinthus Tatarinovii, Ménetriés (loc. cit. Pl. XC., Fig. 16), from Japan, is “pale sea-green, tuberculated with white, with seven lateral, oblique, crimson-edged white stripes.” There is no trace of the subdorsal line shown in the figure, so that this species thus appears to be in the third phyletic stage of development. Smerinthus Planus, Walker, from China (loc. cit. Pl XCII., Fig. 11), is “pale green, with white or yellow lateral stripes.” A trace of the subdorsal line remains on the front segments, thus showing that the species is in the second phyletic stage of development. Triptogon Roseipennis, Butler, from Hakodadi (loc. cit. Pl. XCI., Fig. 6), is represented as yellow, with seven oblique white stripes, with large irregular triangular red spots extending from the anterior edge of the stripes, nearly across each segment. It is probably in the third phyletic stage. The Indian Polyptychus Dentatus, Cramer (loc. cit. Pl. XCI., Fig. 10), is “bluish-green at the sides, with oblique purple stripes, with a broad, dorsal, longitudinal, golden-green band, bordered by subtriangular purple spots, one above each stripe.” The dorsal band is bordered by coloured stripes, which may be the subdorsal lines; but the position in which it is figured, and its very different mode of coloration, make it very difficult to compare satisfactorily with the foregoing species. The genus Ambulyx is closely allied to the Smerinthinæ, and the two following species may be here mentioned: A. Gannascus, Stoll, figured by Burmeister (loc. cit. Pl. XIII., Fig. 5), is green, with a yellow subdorsal line, and seven oblique white lateral stripes, edged with red. A. Liturata, Butl. (loc. cit. Pl. XCI., Fig. 2), is yellowish-green above, passing into bluish-green below. The subdorsal is present on the three front segments, and is followed by a row of white, elongated patches, one on each segment, these being the upper portions of a row of lateral oblique stripes. The thickened upper extremities of the latter are edged with red, and their arrangement is very suggestive of their having arisen from the breaking up of a subdorsal line. R.M.]

105

[Butler catalogues 43 species of this genus. R.M.]

106

The deposition of eggs was accomplished by the insect laying hold of the point of a twig with its legs during flight, and curving its abdomen upwards against a leaf, the wings being kept vibrating. The egg is instantaneously fastened to the leaf. This operation is repeated from twice to four times successively, the moth then hovering over and sucking at the flowers for some time. The eggs exactly resemble in colour the young green buds of Galium.

107

[Figures of a remarkable case of gynandromorphism in a butterfly (Cirrochroa Aoris, Doubl.) have recently been published by Prof. Westwood (Trans. Ent. Soc. 1880, p. 113). On the right fore- and hind-wings of a male specimen there are patches of female colouring, thus bearing out in a very striking manner the above views concerning the non-fusibility of characters (in this case sexual) which have been long fixed. Complete (i. e. half-and-half) gynandromorphism is not uncommon in butterflies. R.M.]

108

[I have long held the opinion that the di- and trimorphism displayed by certain butterflies has originated through polymorphism from ordinary variability. I will not here enter into details, but will only cite a few instances indicating the general direction of the arguments. The phenomenon to which I refer is that so ably treated of by Mr. A. R. Wallace (see Part I., p. 32 (#Page_32), note 20 (#cn_23)) and others. One male has often two or more distinctly coloured females, and in such cases one form of the female generally resembles the male in colour. Cases of polymorphic mimetic females may for the present be excluded, in order to reduce the argument to its greatest simplicity. Thus, in the case of native species, Colias Edusa has two females, one having the orange ground-colour of the male, and the other the well-known light form, var. Helice. So, also, Argynnis Paphia has a normal female and the dark melanic form var. Valezina. Numerous other cases might be mentioned among exotic species; and, looking at the phenomenon as a whole, it is seen to be one of gradation. For instance, our common “Blues” (Plebeius Icarus, P. Thetis, &c.) have females showing a complete gradation between the ordinary blue male and the brown female coloration. In a large number of specimens of Callosune Eupompe in my cabinet, collected in Arabia by the late J. K. Lord, there is a completely graduated series of females, varying from individuals having the scarlet tips of the fore-wings as strongly developed as in the males, to specimens without a trace of such colouring; and the same is the case with other species of this and allied genera. In such instances it is only necessary for the intermediate female forms to become extinct, in order to have true cases of dimorphism. It is significant that in 1877, when Colias Edusa appeared in this country in such extraordinary profusion, large numbers of intermediate forms were captured, these forming an uninterrupted series connecting the normal female and the var. Helice. R.M.]

109

[Many of our best describers of caterpillars, such as the late Edward Newman, Messrs. Hellins and Buckler, &c., have described the various forms of numerous polymorphic species, but not from the point of view of the comparative morphology and ontogeny of the markings. R.M.]

110

[In Butler’s revision both these species are placed in the genus Hemaris. R.M.]

111

[This species is figured also by Butler (loc. cit. Pl. XC., Fig. 9), who represents it with seven oblique green lines between the spiracles and below the subdorsal line. R.M.]

112

“Cat. E. Ind. Co. Mus.,” Pl. VIII., Fig. 2. [Walker, Lepidop. Heter. VIII., p. 92, No. 14, 1856; this species is strictly confined to Java. R.M.]

113

[Eng. ed. The caterpillar is described and figured by Millière, “Iconographie des Chenilles et Lépidoptères inédits,” tome iii., Paris, 1869; also in the Annales, Soc. Linn. de Lyon, 1871 and 1873.] [This sp. = Hemaris Croatica, Esper., of Butler’s revision. R.M.]

114

[The following additional species of the subfamily Macroglossinæ have been figured by Butler: —Lophura Hyas, Walk. (loc. cit. Pl. XC., Figs. 1 and 2), Hong-Kong, Silhet, and Java. The larva is apparently figured in two stages, the younger being red-brown with oblique white stripes, and the head and three front segments green. The larger specimen is green, mottled with red-brown, and no oblique stripes. In both figures the subdorsal line is indicated. The whole colouring is very suggestive of protective resemblance. Hemaris Hylas, Linn., from China, Japan, Ceylon, India, Australia, and Africa (loc. cit. Pl. XC., Fig. 4). The upper part of the body is light blue, and the lower part green, the two areas being separated by a white subdorsal line bordered above with brown. The dorsal line is feebly represented. Macroglossa Belis, Cram., N. India (loc. cit. Pl. XC., Fig. 6), is figured with the ground-colour deep indigo; a conspicuous white subdorsal, and a yellow spiracular line is present; on the side of each segment, between the two lines mentioned, there is a large red spot with a yellow nucleus (? eye-spots), the spots decreasing in size towards the head and tail; these probably confer upon this species some special protective advantage. Macroglossa Pyrrhosticta, Butler, China and Japan (loc. cit. Pl. XC., Fig. 8), is greenish-white with dorsal and subdorsal lines, and seven dark oblique stripes along the sides, below the subdorsal line. Of the foregoing species Hemaris Hyas appears to be in the same phyletic stage as M. Stellatarum and M. Croatica, &c., whilst M. Pyrrhosticta is probably, together with M. Corythus and M. Gilia, in another and more advanced stage, which is also passed through by Lophura Hyas in the course of its ontogenetic development. This last species (adult) and M. Belis may represent phyletic stages still further advanced. Caliomma Pluto, Walk., of which the caterpillar is figured by Burmeister (loc. cit. Pl. XIII., Fig. 1), appears to be a case of special protective resemblance to a twig or branch of its food-plant. Figured also by Chavannes; Bull. Soc. Vadoise des Sci. Nat., Dec. 6th 1854. R.M.]

115

[Genus Pterogon, Boisd., = Proserpinus and Lophura (part). Butler, loc. cit. p. 632. The species above treated of = Proserpinus Œnotheræ, Fabr. R.M.]

116

[These species = Thyreus Abboti and Proserpinus Gauræ of Butler’s revision. Of the former he states: – “Transformations described, and larva and imago figured, Am. Ent. ii. p. 123, 1870; the larva is also figured by Scudder in Harris’s ‘Correspondence,’ Pl. III., Fig. 1 (1869), and by Packard in his ‘Guide,’ p. 276, Fig. 203.” R.M.]

117

[Proserpinus (Sphinx) Gorgon, Esp. R.M.]

118

Rösel, loc. cit. vol. iii., p. 26, note.

119

Figured and described by Abbot and Smith. [Macrosila (Sphinx) Cingulata is figured also by Burmeister, loc. cit. Pl. XII., Fig. 1. R.M.]

120

Figured in “Cat. Lep. E. Ind. Co.”

121

See the figure in Sepp’s Surinam Lepidoptera, P. 3, Pl. CI., 1848. A specimen in alcohol of the adult caterpillar is in the Berlin Museum. [The following is the synonymy of the above mentioned species: —Macrosila Hasdrubal, Walk. = Pseudosphinx (Sphinx) Tetrio, Linn.; M. Cingulata = Protoparce (Sphinx) Cingulata, Fabr.; M. Rustica = Protoparce (Sphinx) Rustica, Fabr.; Sphinx Convolvuli, Linn. = Protoparce Convolvuli; S. Carolina, Linn. = P. Carolina; the other species remain in the genera, as given above. The following additional species of Sphinginæ and Acherontiinæ have been figured by Butler: —Pseudosphinx Cyrtolophia, Butl., from Madras (loc. cit. Pl. XCI., Figs. 11 and 13); Protoparce Orientalis, Butl., from India, China, Java, &c. (Pl. XCI., Fig. 16); Diludia Vates, Butl. from India, &c. (Pl. XCI., Fig. 18); Nephele Hespera, Fabr., from India, Australia, &c. (Pl. XCI., Fig. 20); Acherontia Morta, Hübn., from Java, China, India, &c. (Pl. XCII., Fig. 9); and A. Medusa, Butl., from nearly the same localities as the last (Pl. XCII., Fig. 10). Most of these species fall under Dr. Weismann’s general remarks, so that it is unnecessary to give detailed descriptions. The most divergent marking is that of P. Cyrtolophia, which has a broad white dorsal line bordered with pink, and two large pink ovals on the back of the four anterior segments, the hindmost and larger of these being bisected by the dorsal line. In N. Hespera the subdorsal line is present on segments 6 to 11 only, and it is highly significant that the oblique stripes are absent from these segments, but are present on the anterior segments, where the subdorsal line fails. With reference to the larva of A. Atropos, Mr. Mansel Weale states (Proc. Ent. Soc. 1878, p. v.) that in S. Africa the ordinary form feeds generally on Solanaceæ, whilst the darker and rarer variety is found only on species of Lantana. The following species of these subfamilies are figured by Burmeister: Amphonyx Jatrophæ (loc. cit. Pl. XI., Fig. 1); Protoparce (Diludia) Florestan, Cram. (Fig. 2); Sphinx Justiciæ, Walk. (Fig. 3); Protoparce (Diludia) Lichenea, Walk. (Fig. 4); Sphinx (Protoparce) Cingulata, Fabr. (Pl. XII., Fig. 1); and Sphinx Cestri (Fig. 5). All these species have the characteristic Sphinx-like markings. Dilophonota Ello, Linn. (Pl. XII., Fig. 2), is greenish-brown with a yellow subdorsal line, and D. Hippothöon (Fig. 4), yellow with a whitish subdorsal. Neither of these has oblique stripes. D. Œnotrus, Cram. (Fig. 3), has neither stripes nor subdorsal, but is uniform brown above, passing into green beneath. Protoparce Albiplaga, Walk. (Pl. XIII., Fig. 2, also Mérian, Pl. III., and Abbot and Smith, I., Pl. XXIV.), pale green with large yellow, black-bordered patches surrounding the spiracles. Pseudosphinx Tetrio, Linn. (Pl. XIII., Fig. 3), and P. Scyron (Fig. 4) are black with broad transverse belts, yellow and white respectively, encircling the middle of each segment. These light bands serve very effectively to break up the uniform surface of the large bodies of these insects, but the whole marking is suggestive of distastefulness. R.M.]

122

[The species referred to is placed by Butler in Hübner’s genus Hyloicus. R.M.]