ATTACUS ATLAS: A LIFE-HISTORY. 37 
white parts; and not from the grey, black, and red spots: though 
SO copious is the exudation that these coloured patches are 
considerably encroached-upon by the intrusive substance.* 
On the 26th—ten days after the first moult—one of them, by 
a second moult, passed into the third age. I had observed it at 
9 a.m. the new head projecting, waiting its change, and at 11 all 
was completed. It was on the same leaf as before, just above the 
sand; where the exuvie, if fallen from the leaf would surely have 
been lying ; but I searched in vain for any trace of it, except a tiny 
heap of cylinders of white farina, which, I presume, had clothed 
the old tubercles, and in the middle of these the old skull, or 
rather skin of the face. I could not avoid the conclusion that the 
new-changed larva had made a meal of his cast-off clothes. I had 
many such examples afterwards, and in some instances actually 
saw a good part of the exuviz devoured; so that this habit may 
be considered normal. 
LARVA.—3rd age (newly moulted). 
The larva, in passing into the third age, has not conspicuously changed 
in colour; but by careful examination I detect differences. The general 
ground-hue is a semi-pellucid white. The upper and middle series of 
tubercles, longer and slenderer than before, are white, the lowest series 
blue-black. ‘The first segment is dark grey, between the white bases of the 
tubercles; the hinder three segments are minutely speckled with grey. 
The sides are marked, on each segment, with four diagonal bands, irregular 
in outline, highest behind, of which the upper two are pale grey tinged with 
red, the lower two dark grey. The two irregular clouds of rust-red, on each 
side, are become somewhat wider, and somewhat brighter in hue. The face 
is polished light bay, the lip dark, the cheeks white. Feet and prolegs dark 
grey, with deeper bands: the hindmost prolegs have a thickened margin of 
*I suspect that this substance is a true Wax, analogous to the Pe-la of China, 
and to the White-lac of Madras. (Kirby and Spence, Lett. x.) Having allowed a 
caterpillar to touch the surface of a plate of glass, I examined it by the microscope. 
I saw many groups of very short and very slender fibres, so arranged as to suggest 
that they had been exuded in thin lamine of definite width, which then had partly 
disintegrated (perhaps by contact with the glass) into their component fibrille; for 
they manifestly had been parallel, and still had curves and irregularities of form, in 
common. Having lifted, with care, a minute portion from the tip of a tubercle, by 
the point of a needle, and transferred it to the glass slide, this appeared much more 
as irregular thin plates, of which the fibres, though visible, were much less distinct, 
and less apparently parallel. The substance resembled wax, in its adhesion to the 
glass, aud in the smear it left when moved, 
