Useful Insects and their Products. 423 
constitute, iii fact, a considerable article of commerce from Scio 
to Constantinople, where they are regularly sold in the market. 
Dr. Lankester, referring to these galls, says, that those which pro- 
ject from the branches of the Salvia pomifera — a species of sage 
of peculiar growth, and common to the Greek islands, — are called 
sage-apples, and are supposed to be produced by the puncture of 
a gall-fly. They are about three-quarters of an inch in thickness, 
of a fleshy appearance, and semi-transparent, like jelly. They 
are constantly exposed for sale in the markets of Greece, where 
they are made into a kind of conserve, which is highly esteemed. 
Dr. Clarke assures us of the excellence of this delicacy, with which 
he was regaled by the English consul at the island pf Syros. In 
France, the galls of ground-ivy have been eaten; but Reaumer, 
who tasted them, doubts that they will ever become a part of the 
dessert. The nut-galls which are so extensively used in the black- 
ink manufacture, arise from the punctures which a certain species 
of gall-fly (first described by 01ivier,*under the name of Diplolepsis 
gallce tinctorice) makes in the leaves of a species of oak [Quercus 
infectoria, Oliv.) very common throughout Asia Minor, where, in 
many places, these galls are collected by the poorer people, and 
exported at Smyrna, Aleppo, and other ports in the Levant, as 
well as from the East Indies, whither a part of those collected are 
now carried. The oak-galls most prized are those commonly 
known as blue galls, being those gathered at an early period — that 
is to say, before the gall-flies have been disclosed from the galls. 
Those of the second gathering, from most of which the insects 
have made their escape, are called white galls, and are of an in- 
ferior quality, containing one-third less of the astringent principle 
than the blue galls. Both the white and the blue galls are usually 
imported mixed in about equal proportion, and in this state are 
called galls in sorts. To the dyer, galls are important materials 
for imparting a black color to garments and other articles. This 
can, indeed, be accomplished without the use of galls; yet not- 
w'ithstanding all the improvements.in the art of dyeing, galls are 
found to offer at once the cheapest and most effectual means. 
Molina tells us that in Chili on oil is obtained from the large 
globular cellules found upon the wild rosemary, and which are 
supposed to be galls produced by the punctures of a gall-fly. In 
the East, the west of Europe, the Levant, and Greek islands, cer- 
tain species of gall-flies are of great use in assisting the ripening 
of the hg (^Ficus carica.^ "The fig consists of a pulp, containing 
a number of seed-like pericarps, inclosed in a rind. It has no 
visible flower, for the fruit arises immediately from the joints of 
the tree, in the form of little buds, with a perforation at the end, 
but not opening or showing any thing like petals, or the ordinary 
parts of fructitica'tion. As the fig enlarges, the flower comes to 
