28 
the long, fine, glassy hairs. Maskell, following Signoret's description, 
rightly says that sacchari "does not seem to form an ovisac with longi- 
tudinal grooves." But Signoret himself says that sacchari, in the 
island of Bourbon, "is confounded with Lecanium (jaster alpha, under 
the name of louse-with-the-white-pocket." Whether Signoret assumed 
such confounding by the islanders because of erroneous supposition 
that this sacchari had no ovisac, or whether the islanders designate both 
the Lecanium and the Icenja under the characteristic vernacular, is not 
plain from the language, and is immaterial. On the principle of unity 
of habit in the same genus, I feel morally sure that Signoret's Icerya 
must produce her eggs in such an ovisac, and the Bourbonese are doubt- 
less well aware of the fact, otherwise they would not so indicate it or 
confound it with Lecanium. We are justified in assuming that the 
female which my friend Signoret described and figured had only just 
begun forming its sac, and that its ilutings had become effaced and the 
secretion unnatural in appearance. MaskelFs second reason, viz, that 
sacchari "does not show the great tufts of black hairs and the project- 
ing glassy tubes," will also lose force from the facts that Signoret par- 
ticularly describes these glassy tubes as " long filaments, waxy, very 
fine, delicate, transparent," and that these tufts of black hairs are ex- 
tremely variable in quantity, sometimes making the insect look quite 
dark and bringing out in strong relief the few smooth, orange-red or 
brick-red elevations, and particularly the series of about twenty-two 
around the border ; at other times being so scarce that the insect has 
an almost uniform reddish-brown appearance. 
It would appear, therefore, that, notwithstanding the differences in 
Signoret's and Maskell's characterizations, there is room yet for grave 
doubt as to the specific difference in the two insects, especially as upon 
restudying Signoret's description it accords in every other particular 
with I. purchasi. 
You will pardon me, I know,, for going into these technical details, be- 
cause it is evident that the solution of these questions has a very im- 
portant bearing. My own impression now is that future investigation 
will prove that the two insects are identical. The truth will in time be 
ascertained by getting all the different stages of sacchari from the Isl- 
and of Bourbon or from Mauritius, and comparing them more carefully 
with purch asi, the different stages of which I have fully detailed in my 
report. 
Let me say in this connection that there is. a great variability in ^mr- 
chasi as to the amount of matter secreted on the scale itself, which may 
very easily mislead, especially in dried specimens. In the orange proves 
of Southern California the general colorational aspect of the insect is, 
in all its stages, reddish-brown, the surface exudation being rarely ex- 
cessive and never obliterating the reddish-brown color. This exudation 
is, in fact, more noticeable upon the male larva, which, together with 
his narrower, more elongate form, renders him easily distinguishable 
