152 _ THE ENTOMOLOGIST. 
which at the birth of the caterpillar was bent forwards, and 
after that stood almost straight up, is now bent backwards, 
and is no longer forked, but ends in one sharp point. Full 
grown, the caterpillar appears like fig. 6. Here I must 
observe that all fir-tree arrow-tail caterpillars are not exactly 
marked like this: on some the stripes run right through to’ 
the reverse side of the body, whilst here they are shown 
broken up into little patches; however, besides this, there is 
no other difference in the markings. 
§ 3.—This insect, having completed its life as caterpillar, 
and being now about to undergo its first transformation, or 
become a pupa, creeps into the ground, and there makes this 
change, in the same way as I have already described this 
operation in the description of other arrow-tails. As pupa, it 
appears in the shape, size and colour of fig. 7, having this 
remarkable peculiarity, that the sheath of the sucker of the 
moth, which dwells in the pupa, is somewhat separated from 
the body, and scarcely stuck fast to it by the thick end, there 
being consequently a small opening between them. This is 
also the case with the pupe of the “liguster” and bindweed 
arrow-tai] moth, but not with others. The fir-tree arrow-tail 
pup remain all winter laid in the ground, and the moths 
come out late in the following summer. This second change 
occurs also in all points like that of other moths, so I need 
not make any further remark about it here. 
§ 4.—Our fir-tree arrow-tail moth now having left the 
pupal membrane, and its wings having obtained their proper 
stiffness, appears, when at rest, like fig. 8, that being a female, 
which by its thicker abdomen alone is sufficiently distinguish- 
able from the male, this latter being seen flying at fig. 9. The 
antenne differ very little in the sexes, but those of the 
male are a little thicker and rather more downy. With regard 
to the marking of this insect, it seems at first sight to be 
always alike, but if one looks at it a little closer one finds 
here and there a little difference: the ground colour, namely, 
is not the same exactly in all; a property, which this sort has 
in common with by far most other sorts. 
§ 5.—With regard to our new discovery about the impreg- 
nation of eggs of some moths with foreign eggs, of which I 
made mention in the beginning, I have not yet found any- 
thing like it in any describer of insects; consequently this 
