This object will serve to answer a question which the reader has probably put to himself ere this, namely, Where are the fragrant resins, scents, and oils stored? On Plate I. Fig. 16, will be seen the reply to the first question; Fig. 41 of the present Plate has answered the second question, and Fig. 42 will answer the third. This figure represents a section of the rind of an orange, the flattened cells above constituting the delicate yellow skin, and the great spherical object in the centre being the reservoir in which the fragrant essential oil is stored. The covering is so delicate that it is easily broken, so that even by handling an orange some of the scent is sure to come off on the hands, and when the peel is stripped off and bent double, the reservoirs burst in myriads, and fling their contents to a wonderful distance. This may be easily seen by squeezing a piece of orange peel opposite a lighted candle, and noting the distance over which the oil will pass before reaching the flame, and bursting into little flashes of light. Other examples are given on the same plate. Returning to the barbed hairs, we may see in Fig. 35 a highly magnified view of the “pappus” hair of a dandelion, _i.e._ the hairs which fringe the arms of the parachute-like appendage which is attached to the seed. The whole apparatus will be seen more fully on Plate III. Figs. 44, 45, 46. This hair is composed of a double layer of elongated cells lying closely against each other, and having the ends of each cell jutting out from the original line. A simpler form of a double-celled, or more properly a “duplex” hair, will be seen in Fig. 44. This is one of the hairs from the flower of the marigold and has none of the projecting ends to the cells. In some instances the cell-walls of the hairs become greatly hardened by secondary deposit, and the hairs are then known as spines. Two examples of these are seen in Figs. 37 and 38, the former being picked from the Indian fig-cactus, and well known to those persons who have been foolish enough to handle the fig roughly before feeling it. The wounds which these spines will inflict are said to be very painful, and have been compared to those produced by the sting of the wasp. The latter hair is taken from the Opuntia. These spines must not be confounded with thorns; which latter are modified branches. Fig. 10 represents the extreme tip of a hair from the hollyhock leaf, subjected to a lens of very high power. Many hairs assume a star-like appearance, an aspect which may be produced in different ways. Sometimes a number of simple hairs start from the same base, and by radiating in different directions produce the stellate effect. An example of this kind of hair may be seen in Fig. 14, which is a group of hairs from the hollyhock leaf. There is another mode of producing the star-shape which may be seen in Fig. 45, a hair taken from the leaf of the ivy. Very fine examples may also be found upon the leaf of Deutzia scabra.