The Orientals are very careful to gather in this crop at the exact time which experience has proved to be the best, namely, that in which the excrescence has attained its greatest size and weight. If there is any delay, the insect undergoes its metamorphosis, pierces the shell, and appears under its form of a winged insect. From this time the gall-nut no longer derives from the tree those juices which were necessary for the nourishment of the insect, but dries up, and loses the greater part of those qualities which make it valuable in commerce. The Aga of the district takes care that the cultivators traverse frequently, at the time of the harvest, the hills and mountains which are covered with this oak. He has an interest in obtaining galls of good quality, because he levies a tax on the produce. The first gatherings are set aside; they are known in the East under the name of _yerli_, and are called in commerce _black galls_, and _green galls_. Those which have escaped the first search, and which are gathered a little later, are named _white galls_, and are of a very inferior quality. The galls from Mossoul and Tocat, and in general those which come from the eastern part of Turkey, are less valued than those from the neighbourhood of Aleppo, of Smyrna, Magnesia, Diarbekir, and all the interior of Natolia. The acorns of this oak are nearly always neglected; being left as pasturage for goats and wild boars: this it is thought contributes much to render the oak small and stunted, because in devouring the fruit, these animals also consume a part of its foliage and young branches. The body of the insect which produces the gall-nut, is of a fawn colour, with obscure antennæ; the abdomen is shining brown. It is sometimes found in its perfect form in the interior of the nut. On the same oak are frequently found a great number of other galls, which are not gathered, because they are of no use in dyeing. One of these is represented in the frontispiece to this chapter, and is remarkable for its large size. It is spongy, very light, of a reddish brown colour, and covered with a resinous matter. It is also furnished with a circular range of tubercles, placed near its greatest circumference. This is produced by a different insect, called by Olivier _Diplolepis gallæ resinosæ_; a figure of which is also given on the right hand side.