306 Captain T. Hutton on the 
The Black Worm. (Pl. XIX. fig. 7.)—When first hatched the 
caterpillars are in all respects similar to those of the pale variety, 
and it is not until after the first, and sometimes second, moult has 
taken place that any difference is perceptible; then, however, instead 
of having the four anterior segments of a creamy-white, the whole 
body is ofa dark-brindled or mottled-grey colour, with the exception 
of an ashy band or broad stripe, which, crossing in front of the an- 
terior segment, runs round on each side as far back as the middle 
of the fifth segment, widening up towards the back, but leaving a 
dark-brindled dorsal space between them; at a later stage, when 
the worm is near maturity, this ashy band becomes less clear 
and bright, and is often tinged faintly with clay colour, or even 
with a fleshy roseate hue; on the fifth segment the two dark 
lunules are well defined, and have an ashy patch between them ; 
the dark spots on the eighth segment are sometimes wanting, as 
they are also in the white variety. 
In the third and fourth stages the colouring generally becomes 
very dark, in some intensely so, and takes the form of a net or 
trellis-work spread over an ashy-grey ground. As the worm ap- 
proaches the spinning time the colours again become fainter, and 
often assume a grey sandy-brown hue overlaid by the dark net- 
work. The anterior portion of the second segment rises some- 
what abruptly, and from it, through the dorsal centre of the first, 
runs a narrow black longitudinal line, on each side of which, on 
the second segment, is a round black spot, perpendicularly divided 
by a pale orange line, causing the appearance, as it were, of two 
eyes. 
Such is the appearance in the first year of the separation from 
the white worm; the differences in after years, of course, become 
more marked, though the general character is the same. 
After two or three years of separation and restricted inter- 
breeding the appearance, especially in the middle stages, is very 
dark indeed, and the whole insect looks as if overlaid by a well- 
distended net, the meshes of which are open and well defined ; it 
is, indeed, this well-defined marking, together with the ashy lateral 
band along the anterior segments, which makes the species ap- 
proximate to the wild races, the lateral band more especially being 
a characteristic of the wild worms. 
Progress of the Experiment.—In the previous part of this paper 
(ante, pp. 149—153) I have shown the result of my experiments 
up to the end of 1863. I now proceed to show the condition of 
