Notes in 1887 upon lepidopterous larve, dc. 519 
visible. The dorsal vessel forms a very distinct feature 
throughout the stage. The fact that the green colour of 
the larve is at this stage chiefly dependent upon the 
contents of the digestive tract, was well seen on Sept. 
14th, when a single one out of the fifteen younger larvee 
was found at the end of a shoot, where it had been 
eating the young yellowish leaves. This larva was of a 
much paler green than all the others which had been 
eating the older darker leaves. 
The caudal horn is not so long as in S. ligustri: 
it tapers very slightly from base to apex, and it is held so 
as to nearly make a right angle with the line of the 
back. During this stage it is characterized by a very 
slight curve, with the concavity directed anteriorly, 
conferring upon it a very unusual appearance; for the 
curve in the horn of other Sphingide, and in the two last 
stages of this species, is in the opposite direction. (For 
the general appearance of the horn see Plate XV., fig, 2, 
x 5°8). The bifidity of the horn varies immensely, and 
this is probably true of the younger stages of all other 
Sphinx larve, although they have not been examined 
with equal care. ‘These extreme individual differences 
are to be expected because of the vestigial nature of the 
part in question. The larva hatched Sept. 7th possessed 
the most strongly marked fork: it is shown from the 
front in Plate XV., fig. 3, x 50. The terminal bristles 
are seen to be stout; and each ends in a very slight 
knob, while the rest of the horn (of which only the 
upper part is shown in detail in fig. 3), is clothed with 
thickly crowded minute short hairs, each springing from 
a tubercular base. ‘The structure is thus very different 
from that of the two next stages in which the horn 
presents a thorny appearance, due to the presence of a 
much smaller number of far larger hairs and tubercles. 
\Compare figs. 3 and 4, with 9 and 16, Plate XV.). Iam 
now able to state that the caudal horn of S. ligustri, in 
the first stage, is similar to that just described, and 
bears the same relation to the stages which immediately 
follow. One of the younger larve also possessed a 
deeply-notched horn, but not so pronounced as that repre- 
sented in fig.3. The ends of all the horns of other larve 
were much like that shown in fig. 4, x 50, some having 
a rather deeper notch. The dark colour of the horn 
