232 BULLETIN: MUSEUM OF COMPARATIVE ZOÖLOGY. 
7. Landois (64) demonstrated that the “blood,” or hemolymph, of 
Lepidopterous larvæ contained egg albumen, globulin, fibrin, and iron. 
In addition to this Poulton ('85) found that the blood of leaf-cating 
larvee often contained chlorophyll and xanthophyll derived from their 
food plants. 
I find that the hamolymph of the pups of the Saturnide contains 
egg albumen, globulin, fibrin, xanthophyll, and orthophosphoric acid. 
Mr. George Oenslager has kindly determined for me that iron, potas- 
sium, and sodium are also present. 
8. Landois (64) pointed out the fact that the color of the dried 
blood of many Lepidopterous larve is similar to the ground color: of 
the wings of the mature insect. 
I here produce evidence tending to prove that the pigments of the 
scales are actually derived, by chemical processes, from the heemolymph 
of the pupa. My reasons for believing this are as follows : — (1) I can 
find nothing but hemolymph within the scales during the period of the 
formation of pigment. (2) In all Lepidoptera the first color to appear 
upon the pupal wings is a dull ochre-yellow, or drab, and this is also the 
color which is assumed by the hemolymph when it is removed from the 
chrysalis and exposed to the air. (3) I have succeeded, by artificial 
means, in manufacturing several pigments from the hemolymph, which 
are similar in color to various markings upon the wing of the mature 
insect; chemical reagents have the same effect upon these manufac- 
tured pigments that they do upon the similarly colored pigments of 
the wings. 
9. Dull ochre-yellows and drabs are, phylogenetically speaking, the 
oldest, pigmental colors in the Lepidoptera ; for these are the colors that 
are assumed by the heemolymph upon mere exposure to the air. The 
more brilliant pigmental colors, such as bright yellows, reds, greens, 
etc, are derived by more complex chemical processes. We find that 
dull ochre-yellows and drabs are at the present day the prevalent colors 
among the less differentiated nocturnal moths. The diurnal forms of 
Lepidoptera have almost a monopoly of the brilliant colorations, but even 
in these diurnal forms one finds that dull yellow or drab colors are still 
quite common upon those parts of their wings that are hidden from 
view. 
In conclusion, it is a privilege to express my gratitude to those gen- 
erous friends to whose kindness is due much that may be deemed of 
value in this research. To Professor Edward L. Mark I am indebted 
