early stages of Latiorina orbitulus. 1538 
In order that this fact may be fully demonstrated and 
not rest merely on my apse dixit, I present photographs of 
the skin of the larva at each stage, and enlarged ones of 
the region of the seventh abdominal segment, where the 
honey-gland would be, if present. They show, instead, 
hairs precisely as in the other segments, or rather in their 
proper order as varying a little from segment to segment. 
The photograph of the prothorax (Pl. IX) shows the 
change in the character of the hair bases at the last moult, 
and both show very well the peculiar angular hair of the 
late. 
. The detailed plates of the pupa-skin show the nature 
of the sculpture and armature in different regions, in a 
way more easily useful to any one interested than a 
prolonged description. 
Herr Viehmeyer, who has specialised on the honey- 
glands of Lycaenid larvae, has only met with V. (Lycaena) 
optilete as a species amongst our Kuropean “ Blues” with- 
out the honey-gland, and this only on the basis of blown 
specimen in the Staudinger collection. There can be no 
doubt, however, that such evidence is quite trustworthy. 
It is tolerably certain that pyrenaica, the Pyrenean cousin 
of orbitulus, will be found to agree with it in this respect. 
The possession of a honey-gland is so universal in the 
Blues as to be almost a subfamily character, and one 
inclines to search for reasons for including in the 
Lycaenines those species usually placed in other sub- 
families that possess this remarkable organ. How are we 
to explain its absence in these species which are- typical 
Lycaenines, and cannot be located by any excuse outside 
the subfamily ? 
Why they are without it is possibly because they are 
such high-level species that few, if any, ants exist in their 
habitats; optilete and orbitulus, with pheretes, whose larva 
is practically unknown, are the species having their 
habitats at the highest level of all the European Blues 
(from 6000 to 8000 ft. in the Alps, rarely somewhat 
lower, especially in the case of optilete). What the numbers 
and activities of ants are at this elevation I do not know; 
it is a point that wants investigating. 
This may be a “ final cause” for these species wanting 
the honey-gland. A more important question is, have 
they lost it, or did they never possess it? If they never 
had it, then these species must be ancestral to all the 
