Chap. 11.] 
CACHETS. 
351 
and a production which closely resembles the mulberry, ex- 
cept that it differs from it in being dry and hard : for the most 
part it bears a resemblance to a bull's head, and in the inside 
there is a fruit very similar to the stone of the olive. Little 
balls'*^ also are found growing on the robur, not unlike nuts in 
appearance, and containing within them a kind of soft wool, 
which is used for burning in lamps ; for it will keep burning 
without oil, which is the case also with the black gall-nut. 
It bears another kind, too, of little ball, covered with hair,"^^ but 
used for no purpose : in spring, however, this contains a juice like 
honey. In the hollows formed by the union of the trunk and 
branches of this tree there are found also small round balls, 
which adhere bodily to the bark, and not by means of a stalk : 
at the point of junction they are white, but the rest of the 
body is spotted all over with black : inside they are of a scarlet 
colour, but on opening them they are found to be empty, and 
are of a bitter taste. 
Sometimes, too, the robur bears a kind of pumice,^^ as well 
as little balls, which are formed of the leaves rolled up ; upon 
the veins of the leaves, too, there are watery pustules, of a 
whitish hue, and transparent while they are soft ; in these a 
kind of gnat*^^ is produced, and they come to maturity just in 
the same way that the ordinary gall-nut does. 
CHAP. 11. (8.) CACHETS. 
The robur bears cachrys,'''^ too ; such being the name given 
of the cynips, deposited upon the leaf or bark of the tree. Tan and gallic 
acid are its principal component parts. 
^3 A substance quite unknown now ; but it is very doubtful if Pliny is 
rightly informed here. 
^0 A fungous gall, produced by the Cynips fungosa. It is not used for 
any domestic purpose at the present day. 
"'^ This kind of gall is now unknown. Fee questions the assertion about 
its juice. 
"^'^ The Cynips quercus baccarum of Linnseus, one of the common galls. 
'^^ The root cynips, the Cynips radicum of Fourcroi, produces these 
galls, which lie near the root, and have the appearance of ligneous nodo- 
sities. It is harder than wood, and contains cells, in which the larva of the 
insect lies coiled up. 
''^ This is a proof, as Fee remarks, that the ancients had observed the 
existence of the cynips ; though, at the same time, it is equally evident 
that they did not know the important part it acts in the formation of the 
gall. 
This word, as employed by Theophrastus, means a catkin, the Juius 
