the other with the greatest ease. Then your hat will be scraped off, your face will be scratched, and you will feel like saying something wicked. You think you see a bird sitting on a nest in one of the trees, and at the risk of your neck climb up to it, only to find it empty. When you reach the ground again, it is with a dozen thorns in your leg, more in your hands, and your face and neck bleeding from scratches. Should you try to sit down, you will find yourself located on a patch of ground already occupied by thousands of the sharpest kind of thorns; by this time you will probably have come to the conclusion that a mesquite patch is no place for a picnic and you vacate the premises.

Associated with the Acacia greggii, with yellow flowers in racemes, and long and crooked pods, is the Acacia farnesiana, a shrub from six to ten feet high, bearing great numbers of small yellow balls of flowers, which are very sweet scented. It is largely cultivated in China for the sake of the flowers, for out of them is made a delicious perfume. The creosote plant, Larrea mexicana, is very abundant on the deserts about Tucson, but a more worthless plant it would probably be difficult to find. Torrey says it is used externally for rheumatism; but no animal seems to feed upon it, and it is useless for fuel, for it can scarcely be made to burn. It has been the subject of much discussion in California, and papers read before the Academy of Natural Sciences say that it produces such quantities of "lac dye," that a profitable business could be carried on by collecting and exporting it. As far as I have observed in examining a large number of bushes, a very small proportion only produces the material for the dye, and these in such small quantities as to make it hardly worth the trouble of gathering.

Still another very common and at the same time a very curious plant is the Fouquiera splendens, one of the Tamariscineæ, and known to the Mexicans as "ochotilla." It grows all over the deserts of Arizona and among the rocks on the mountains. The branches. are long and whip-like, armed with innumerable sharp, curved thorns an inch or more long. The flowers are of a bright scarlet, and form racemes at the ends of the branches. The leaves are threeparted, sessile, and generally appear after the flowers have gone. It is used very extensively by the Mexicans for fences, and oftentimes one sees a fence of this plant, the pieces stuck into the 1 Torrey's Report in Emory's Reconnoissance of N. Mex. and Cal., p. 138.

ground and bound together with raw hide and bunches of the bright scarlet flowers at the top of the stalk. The plant is cer

FIG. 2.-Flowers of Fouquiera (spinosa) splendens Engelm.

tainly one of the most striking of all found on the deserts of Arizona.

Another form is the "Palo erde" of the Mexicans. It is the Parkinsonia torreyana, one of the Leguminosa. It grows to be some fifteen or twenty feet high, and all the branches are of a light-green color. The flowers are of a bright yellow, in long racemes, and quite sweet-scented. Those trees noticed on the Colorado desert were surrounded by swarms of bees, apparently finding excellent food among the blossoms. When in flower, no leaves are to be seen, and when these come out they are very small and inconspicuous.

The cacti form a most conspicuous feature of mountain and desert. By far the most conspicuous and remarkable form is the Cereus giganteus, locally known as the "saguara" cactus. It was first brought to the notice of the scientific world by Emory's Expedition from Fort Leavenworth to San Diego, in 1848, and in his report was given its present name. It is an upright fluted or ribbed pillar, each rib covered from bottom to top with a mass of sharp, straight thorns. At the top of the stem are the long tubular white flowers, with the petals just peeping from the calyx, and with the interior filled with an innumerable mass of stamens. After the fruit is formed the flower, in drying, has the pleasant odor of Calycanthus. When ripe the fruit splits open at the top, displaying the bright red scarlet of the interior, do tted with the

numerous small black seeds. It is much relished by the Mexicans, but to me has a mucilaginous and sweet, but insipid taste.

Birds are very fond of it and often secure it before any one else can get it. The bright red color of the inside of the fruit can be

seen a long way, and doubtless serves to attract birds who can thus disseminate the seeds.

There is no more striking and conspicuous form of vegetation than this Cereus giganteus. It often grows to the height of thirty feet, straight as an arrow and of nearly the same size from bottom to top. The internal framework is made up of a number of hard woody cylinders, the spaces between being filled up by pithy matter; sometimes it is branched, but in a stiff and ungraceful manner, the branches jutting out almost at right angles and then turning and ascending parallel to the parent stem. Sitting on the rocks near some of these plants, when the wind was blowing strongly, the sound of it passing between the spines resembled strikingly the soughing of the wind through the branches of a pine tree; and shutting the eyes it required but little imagination to be transported to a northern pine forest, listening to the wind blowing through the branches. It is strange that the action of the wind in two such different localities as the hot deserts of the South and the cool mountains of the North; and playing upon two such different types of vegetation as a cactus and a pine tree, should produce sounds so similar to each other.

Another species of the family is one commonly called the nigger-head" or "barrel" cactus, a Mammalaria. This often grows four feet high, sometimes only half as much, and almost globular in shape. It has many ribs converging to the top, and each bears innumerable clusters of spines. The lower ones are long, straight and horizontal; some of the central ones stand upright and the largest in each cluster is curved over so as to form a sharp hook. These are very tough, and while the crooked ones serve the Indians for fish hooks, the straight ones are used as needles. The flowers of this species are generally red. A much smaller species of this form, also a Mammalaria, is very common among the rocks on the mountains near the city. The spines are black and very small, but sharp. Still another species (Opuntia arborescens) grows sometimes to be almost a tree, and is covered with a mass of the most awful looking, and feeling thorns. These seem to be covered with a sort of sheath, easily removed, and easily sticking into one's fingers. The thorns are sharp enough and long enough to go through pantaloons and boot top, and stick viciously into the skin. The Mexicans call this the "ochoya" cactus,

and often finding a straight plant and about the right size, will clean off the thorns, and then by much labor clean out the pith from the stem, leaving a stick which is full of holes of all sizes, and which makes a useful and ornamental cane. Then the common prickly pear (Opuntia) forms immense patches, covering acres of ground, and sometimes forming hedges eight and ten feet high. The fruit is known as a "tuni," and is eaten by the Indians and Mexicans. It is of a very mucilaginous nature, sweet and insipid, but not very palatable to ordinary tastes.

It is characteristic of many of the plants of the desert to be provided with thorns, and where there are many thorns there is relatively a small amount of leaf surface. The immense number of cacti are by no means the only spine-bearing plants, and one of the most remarkable, outside of that family, is the Holacantha emoryi. This grows in the dryest and most barren spots of the desert, and forms a large mass of what appears to be nearly all branches and thorns, but it is intermixed with innumerable clusters of small yellow flowers. The small leaves are not apparent when the plant is in bloom, but come out soon afterward. Another plant of a peculiar character, common at Tombstone, seventy-five miles south-east of Tucson, is the Nolina texana. It has a long branching spike of white flowers, intermixed with. linear, sharp-pointed leaves. At the base of the stem great numbers of long sharp leaves spring in all directions, some being eighteen inches or more long, and presenting a formidable appearance. It abounds in the dryest localities.

Besides the desert itself, with its peculiar flora, there are one or two other places in the vicinity of Tucson which are excellent for plant gathering. One is in a patch of low ground where a small stream has been dammed up forming a pond which serves to keep the ground in the vicinity quite moist. Here some few familiar forms are to be found, mixed with others entirely unfamiliar. Among the former, growing very luxuriantly, is the Ampelopsis quinquefolia, apparently the same as the eastern form, Cephalanthus occidentalis, Apocynum cannabinum, Samolus valerandi var. americanus, Medicago sativa, Scirpus olneyi, similar to S. pungens, and Juncus balticus, a native of Europe as well as of the Eastern United States. Among the unfamiliar forms is Amorpha californica, a small shrub with pinnate leaves and long racemes of purple flowers, very similar in appearance to A. fruti