PHYSIOLOGY OF THE LWERTEBRATA. 163 



a less absorption, extending to D, of which '' the part 

 from 59-60 corresponds to the second band of the less refran- 

 gible ])art of the s])ectrum and the third band of true chloro- 

 phyll. The vdolet end is completely absorbed from 51.5, 

 dimmed to 52, but on widening the slit a little, blue comes 

 through on the violet side of 48, but very dimly." With a 

 thickness of 3 mm, the blood gives no absorption of the red, 

 but shows three bands at the violet end (Fig. 31, sp. 6). 

 The blood of the pupa of S. Ligustri is a yellow colour in 

 those individuals which have fed upon privet in the larval 

 state, and greenish-yellow in those which have fed upon 

 lilac. " Comparing the spectra of the blood from pupae 

 of which the larva3 had fed upon different foods, it was found 

 that the lilac-fed individuals showed greater effect at the 

 red end than the privet-fed individuals, while the converse 

 was true of the violet end. The comparison was made in a 

 thickness of about 8 mm. and by sunlight."' 



The table on p. 164 gives the spectra of the blood obtained 

 from various Lepidopterous pupa?. 



After adding absolute alcohol to the blood of the pupa of 

 ;S'. Ocellati(>i, a bright yellow solution of xanthophyll was ob- 

 tained, which gave ' ' the characteristic spectrum (shifted to 

 the violet) 49-47, 45.25-44, the violet being absorbed at 



42." 



Alcoholic extracts of the ova of U. Angidaria, S. Tilicr.', 

 >S'. Occllatus, and Sphin': Lvjustri gave each the spectrum of 

 xanthophyll. 



Poulton has made a comparison of the above results with 

 those yielded by unaltered plant pigments. In Fig, 31, sp. 4 

 and 5, are given the spectra of two and five calceolaria* leaves 

 (superi)osed) respectively. " Comparing these two spectra 

 with those of (jrcrn blood (Fig. 31, sp. i, 2, and 3), the re- 

 semblance is seen to be very great, the chief differences being 

 in the second and third bands of the red end, which are con- 

 tinuous (Fig. 31, sp. 2 and 3), while the third is developed 



* The same results were seen in the leaves of other plants. 



