more numerous than the 2nd stadium developments of the other Sphingid 
groups, except perhaps Hermans, which is very Amorphid as regards 
this character ; and in Amorphinae it is a portion only of these hairs 
which develops the mammillary bases, the remainder undergoing no 
further development but a gradual atrophy, as do the actual seta* on 
the mammillary bases themselves. Hemaris tityus | forms a link 
between the Amorphinae, and the other Sphingid groups in respect of 
the development of these secondary hairs. It has, as with the other 
groups, the primitive 1st stadium that is wanting in Amorphinae, the pri¬ 
mary seta; standing out clearly and alone on the bare skin surface. The 
absence of secondary hairs in Hemaris is the more accentuated by 
reason of the large size and the highly forked character of the 
primaries ? i, ii, iii,iv and v, while in its 2nd stadium the usual Sphingid 
change of the primary hairs being replaced by a coat of secondaries, is 
also rendered more remarkable by the contrast between the unusual 
size of the 1st skin primary hairs and the enormous reduction in their 
size which takes place after the moult; they can only be detected 
from the secondaries, which they closely resemble, by their slightly 
larger size. In H. tityus, however, instead of the secondary coat being 
but poorly developed, and of a more or less evanescent character, as is 
normally the case; it is dense and very strongly developed, and persists 
until larval maturity. II. tityus in its 2nd stadium is more Amorphid 
(Smerinthid) than Amorphinae (Smerinthus ) itself, in respect of the 
density of growth, size and forkedness of the bristles; while the 3rd 
instar of H. tityus is hut little more advanced in respect of the waning 
of these features, and the development of the bases of certain hairs 
into mammillae than the 1st of Amorphinae (Smerinthus), and is 
certainly not so advanced as Amorpha popuii in its 2nd instar. The 
bearing of the above notes on the question whether the smooth-skinned 
larvie having only the primary seta; present, or those of Amorphinae 
with their dense growth of secondary hairs in 1st in star, are to he 
considered as the more primitive form of Sphingid caterpillars, is, 1 
think, clear and conclusive. 
The argument that, because the caudal horn bears a bristly 
coat in the 1st instar of the larvae of all groups, it therefore follows 
that this coat at one time covered the entire body, to he subsequently 
lost on the 1st skin of those of all the groups but Amorphinae, where its 
retention is a sign of the generalized nature of the group, is, I think, 
quite unwarranted. It is difficult to imagine why the larva should 
develope a dense growth of bristles in its 1st instar, and at a subsequent 
period lose it entirely on the body but retain it on the horn, and then, 
after a naked stadium, redevelop or partially redevelop it in a later 
instar. Besides, the course of ontogeny in Sphingid lame, as we at 
present know them, towards nakedness is to lose not only the second¬ 
ary, but the primary hairs as well; hut the primary setie in the 1st 
instar of, say, Sphinx liyustri, are not by any means atrophied. It 
would seem, therefore, that a change which swept away the secondary 
hairs from the body surface as apart from the horn, and yet left the 
primaries intact, would he, to say the least of it, a remarkable one, and 
must have been quite separate and unconnected with the present trend 
+ For my full notes on larvie of Hemaris tityus see vol. iv. of Tult’s British 
Lepidoptera, now in the press. 
