. The physiology of the Invertebrata. en, although the larva and pupa are ?.entirely opaque, while the eggs are white. It is possible!that in this case the conspicuous colours—which warn enemiesthat the species is distasteful—have been recently acquired,!and in consequence of the complete opacity, there would beno advantage in losing the colour of the blood. In the experiments just mentioned, Poulton used a paraffinlamp as a means of illumination, but he afterwards foundthat by the aid of sunlight the spectra were further concentrated green blood of the larva of P. meticulosa,whe
. The physiology of the Invertebrata. en, although the larva and pupa are ?.entirely opaque, while the eggs are white. It is possible!that in this case the conspicuous colours—which warn enemiesthat the species is distasteful—have been recently acquired,!and in consequence of the complete opacity, there would beno advantage in losing the colour of the blood. In the experiments just mentioned, Poulton used a paraffinlamp as a means of illumination, but he afterwards foundthat by the aid of sunlight the spectra were further concentrated green blood of the larva of P. meticulosa,when examined by sunlight, gave the spectrum representedin Fig. 31, sp. I. The band in the red, reaching , was very black, except at the edges. When thisband was most distinct and clear, the violet end was absorbedto 51, darkened to 52. On opening the slit a little, the bluecame through (though dimmed) at 48, the violet end beingabsorbed at 43. When the slit was very narrow, traces of PHYSIOLOGY OF THE INVERTEBhATA. i6[. Fig. 31.—Spectra of the Blood of Lepidopterous Larv^ss and Pup^.(After E. B. Poulton. ) Spectrum i.—The blood of the larva of P. Meticulosa (green variety) examined in a thiclcness of about .75 mm. by sunlight. The blood had been allowed to remain in an open capillary tube for about four days, and was then sealed up after it had evaporated to half its 2.—The fresh and unaltered blood of the pupa of 5. Ligustri, examined in a thickness of 35 mm. by 3.—The fresh and unaltered blood of the pupa of P. Bucephalus, examined in a thickness of 23 mm. by 4.—Two fresh calceolaria leaves, gently compressed, and examined by 5.—Five ditto 6.—The fresh and unaltered blood of the pupa of S. Ligustri, examined in a, thickness of 3 mm. by illumination from the bright sky near the sun. L 162 PHYSIOLOGY OF THE INVERTEBRATA. another band, from , were faintly seen T
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectinverte, bookyear1892
