29 
from the female. In the more northern parts of the State, however, I 
found that the general colorational aspect was quite different, owing to 
the greater excess of the surface exudation, which frequently covers the 
body in little globular masses and gives it a whitish and even greenish 
aspect, and which often rises along the middle of the body into a tufted 
ridge. This form corresponds more nearly with what Signoret has de- 
scribed, and it follows that this waxy surface exudation becomes denser 
and still more noticeable by contraction in the dried or cabinet speci- 
mens or whenever the insect has shrunken. 
This question of the synonymy of the species bears directly on its 
original source; for if we have but one species of the genus, or even if 
there be two, and I. purchasi is found to occur on the sugar cane in the 
islands of Bourbon and Mauritius, then the presumption will be that it 
originally came from these islands. In my address at Riverside, I 
called attention to the fact that this Fluted Scale seems to have become 
notably injurious almost simultaneously in Australia, South Africa, and 
California, and on the assumption that it infests the sugar cane on the 
islands mentioned, it is much more easy to understand its introduction 
to the other countries. Sugar is exported from those islands into many 
parts of the world. The sugar, as it leaves those islands, is very coarse, 
and all the molasses or sirup is not extracted, centrifugals not being 
in use. For the purpose of draining, the sugar-makers are in the habit 
of putting a piece of cane in every hogshead, and, in addition, the top 
is sometimes covered with pieces of cane. In point of fact, I am in 
formed that an insect, known in the trade as the sugar-louse, is of quite 
frequent occurrence in such sugar, and Professor Wiley, of the Depart- 
ment of Agriculture, upon being shown specimens of Icerya purchasi 
(and he is quite familiar with the so-called sugar-louse), informed me 
that he thinks them identical. 
On this hypothesis the initial spreading point is from some of the Pacific 
islands, and the insect probably made its way first to Cape Town and 
thence to Australia, New Zealand, and California. This does not pre- 
clude the possibility of its importation upon other plants, but I think 
it highly probable that the chief method of distribution of an insect 
which is so tough as to bear long survival without food was upon sugar- 
cane in sugar hogsheads, or bags, as it could be much more safely carried 
in this way than upon living plants. The determination of the original 
source of the pest is of vital concern in any study of its parasites, as 
such would be more apt to be found in its native country than in any 
countries of its introduction. 
I have been quite anxious to settle definitely this question of its origi- 
nal home, and have lately had some correspondence with parties in Aus- 
tralia, New Zealand, and Africa. The following extracts from such 
correspondence will prove of interest to the people of California. Mr. 
Kirk’s statement will add weight to the hypothesis that I have ventured, 
while Baron von Mueller’s statement also strengthens it. It may per- 
