THE SUBSTITUTE. 
53 
treatment I find best for all 
under-ground pupse, — Thomas 
Chapman, Glasgow ; November 3, 
1856. 
“ Descriptions of some species of 
Lepidopterous Insects belonging to 
the genus Oikeficus.” By J. 0. 
Westwood, F.L.S. — The above 
is the title of a paper by Mr. 
Westwood, published in the 
‘ Proceedings of the Zoological 
Society of London for 1854.’ The 
genus Oiketicus, though it will 
sound strange to some of our 
readers, is here made to comprise 
the Penthophora nigricans of Cur- 
tis, and the Psyche nigricans of 
the ‘ Manual,’ hut the other spe- 
cies spoken of by Mr. Westwood 
are exotic. As the paper will 
probably be seen by few of our 
readers, and as it is unusually well 
written, the following extracts 
may be acceptable. 
“ It may probably be regarded 
as one of the settled axioms in 
Natural History, that there is not 
a single character which has been 
employed to distinguish any group 
of considerable extent which is not 
liable to be effaced, or even con- 
tradicted, by some one or more of 
the niembers thereof. Thus, whilst 
we have quadrupeds without legs, 
and birds without wings, the great 
division of annulose animals, cha- 
racterised by the possession of ar- 
ticulated feet, contains great num- 
bers of species which are entirely 
destitute of these organs ; and in 
like manner the secondary division 
of the Annulosa, distinguished by 
the possession of wings in the final 
state (or the Plilota of Aristotle), 
exhibits to us many species which 
never gain instruments of flight. 
Instances, however, in which both 
these grand characteristics are 
absent, are of the greatest rarity. 
Of wingless Ptilota examples 
occur in most of the orders ; as in 
the female glow-worm among the 
Coleoplera ; the neuter ant and 
female Mutilla among the Hyme- 
noptera ; many of the smaller 
grasshoppers and locusts among 
the Orthoptcra ; some of the Ger- 
ridcB among the Hemiptera; the 
genera Borens and Termes in the 
Neuroptera; the female Coccus 
among the //omoptera; the genera 
Cheonea and Borborus among the 
Diptera ; the Slylopidce, in the 
order Strepsiptera, and the females 
of various moths, as in the genera 
Orgyia and Cheimatobia, as well 
as in Oiketicus of L. Guilding. 
Amongst these exceptions it will 
be remarked that the majority are 
cases in whieh only the females 
are wingless, whilst all except 
Coccus, Stylops, and Oiketicus, 
possess articulated feet in the 
wingless state. These three ge- 
nera would therefore be regarded, 
if we considered only the adult 
state of the females, as the most 
degraded instances of apiropodous 
Ptilota. But such an opinion 
cannot be maintained, since the 
early states of these insects exhibit 
as high an amount of organisation 
as those of any of the other in- 
sects in the orders to which they 
respectively belong, their peculiar 
characteristic being, that, whilst 
in the great mass of winged in- 
sects there is always a gradual 
evolution of structure by which at 
length legs and wings are deve- 
loped, these particular indivi- 
duals, destined ultimately to ap- 
pear in Such a degraded condition, 
not only gradually lose their 
powers of evolution but are sub- 
jected to a power of absorption by 
F 3 
