is excited by a half day's walk under a scorching sun in this excessively dry atmosphere; but from the incredible quantity I drank of this water, so offensive to the palate, I suffered not the slightest inconvenience afterwards.

From New River we pass forth again to a dreary stretch of sandy waste. Heaps of white bones half buried under sand drifts by the wayside, mark the point where years ago a large herd of beef cattle perished in the attempt to drive them by this road from the rich grassy valleys of Sonora to the commanding markets of the Californian coast. The afternoon heat was intense, and one felt more than willing to pause and rest a while as often as one found a creasote bush tall enough to give a little shade. Owing to the several delays made during the day, the deep evening shadows, as they fell, found me some miles from the station; but the road being clearly traceable, there was no danger of missing one's way, and the walk by starlight, in the cooler air, was not unpleasant. As I entered now another belt of low mezquit wood, the light evening breeze came laden with delightful perfume very much like that of pond lilies. But for the loose, dry, yielding earth beneath my feet I could, in the darkness, have fancied myself near the margin of some far northern lake in June, when thousands of those queenly flowers rest on the bosom of placid waters, and breathe “sabean odors" on the air of night. From thoughts of distant lands, and memories of "days that are no more." I was called back to the present by the significant and just now not unwelcome sound of a bull dog's bark, announcing the proximity of my place of shelter for the night, or at least of what I had looked forward to as such; but in fact, this one particular station, when reached, appeared so filthy and ill kept that I was loth to accept a lodging under its roof. After supper as I sat outside the door, I descried, by the light of the rising moon, some bales of hay near the stable, and, as the night air was mild, I asked and readily obtained permission to sleep on a bale of hay. Here I lay, wakeful for a long hour, watching by the moonlight the gambols of a wolf from the desert. This frolicsome beast amused himself and me by capering and yelping around the chained watch dog, greatly to the annoyance of the latter, who evidently wished himself free for a good chase or a fair fight.

In the early morning search was made for the flowers, whatever they might be, which had breathed forth such grateful incense on

the evening air. They were not soon discovered. The parched earth showed nowhere grass or herb of any sort. One cottonwood which the ranchman's axe had spared, stood fair and bright in its fresh spring foliage; but the mezquit trees, notwithstanding the high temperature of these latter days of February, showed yet no sign of leaf or blossom; the larger of these, however, seemed burdened with heavy tufts of a dark green parasite -a species of mistletoe (Phoradendron californicum Nutt). This mistletoe, upon a close inspection, was found bearing a profusion of small, greenish and altogether inconspicuous flowers, with precisely the fragrance of pond lilies; and so the pleasant riddle of the previous night was solved.

The fourth day's travel brought nothing new or specially interesting in the line of the botanical; but the larger size of the mezquit trees, and the more frequent occurrence of them would have indicated, even if the miles had not been counted, that we were nearing, gradually, the banks of the Colorado, the eastern boundary of the desert. And here let us notice more particularly this characteristic and most important of the native trees of the far Southwest, the common mezquit (Prosopis juliflora DC.). To give a general idea of the species, we will compare it with the honey locust (Gleditschia triacanthus L.) a tree well known almost everywhere east of the Mississippi, and not remotely allied to the mezquit. The two species, in several points, very strongly resemble each other. The leaves and flowers of both are much alike, and both have their branches armed with stout, forbidding thorns. But while the honey locust grows erect and displays a well shaped head, the massive trunks of the mezquit usually almost recline upon the ground for about two-thirds of their length; and there are commonly four or five of these half reclining trunks growing from one root; so that a good forest of mezquit, which would really, if cut down, yield a vast amount of wood, looks more like a straggling orchard of old and deformed apple trees than like what would be called a fine piece of timber. The fruit pods, borne in heavy clusters, are as long as those of the honey locust, but very narrow' hardly the fourth of an inch in width, thin and flat; and instead of the sweet reddish pulp of the locust pod, the mezquit has its seeds imbedded in an abundance of a hard, white substance, very sweet, and which the chemists tell us is grape sugar in a state of great purity. Horses, horned cattle

and swine are very fond of these mezquit beans, as they are called, and fatten rapidly when fed on them. Moreover, the "mezquit meal," which Indians and Mexicans manufacture by drying and grinding these pods and their contents, is perhaps the most nutritious breadstuff in use among any people, barbarous or civilized. In these regions where no grass grows, and where the growing of the cereals is limited to the valleys of rivers that are few and far between, the importance of the mezquit, from an economic point of view can hardly be overestimated. The wood burns with an intensity of heat that is unfavorable to the nicest results in baking, and also destructive to iron; hence the few setlers on mezquit lands who brought stoves along, use any other wood rather than mezquit to burn in them, but the best of charcoal is made from it. They assure us that this species of timber possesses the singular property of seasoning without undergoing any perceptible shrinkage. Freighters and immigrants passing over these desert regions, where of course there are no such things as wagon shops for hundreds of miles together, being obliged to do their own wagon repairing, always replace the broken spoke or felly with one made from green mezquit, and the new piece does not shrink away and become loose and useless as it would if made of, for example, a stick of unseasoned oak.

Besides this common and most useful species there is another, called the screw mezquit (Prosopis pubescens Benth.), on account of its short pods being closely twisted into the shape of a screw. This is a smaller tree, of no importance except that its pods have the same nutritious properties as those of the larger and more

common sort.

Having now become familiar with all the principal trees, bushes and herbs of the great, desolate wilderness, I was not sorry when I knew myself to be approaching the banks of the Colorado and the habitations of civilized men. During five days I had never met a fellow traveler of any complexion on the road save that gang of naked giants, the Yumas before referred to. therefore a new and rather pleasant species of incident that befell me when within thirty-five miles of my journey's end I met a pedestrian of my own color. It was a fair haired, handsome French boy of eighteen or twenty years, who came plodding along through the heated sands in his stocking feet, and carrying over his shoulder a pair of new boots. His brand new suit of

army blue, together with the manifestly unquiet condition of his nerves, told all too plainly the tale of desertion from the U. S. Army. His first words when we met were to ask how far it was to water. I pitied him most sincerely, for I had to answer “at least ten miles;" at which discouraging news he, however, stamped the sand in such emphatic wrath, and gave vent to such a volume of French profanity, as quite satisfied me that he was good for the ten miles even without refreshment. He had taken French leave of Fort Yuma on the Colorado early in the course of the previous night, and was now at midday full thirty-five miles out upon the desert, on his way to San Diego. Not having dared to appear before the inmates of the one station he had passed, he was now sorely pressed by thirst and hunger, and also harassed by the fear of falling into the hands of possible pursuers. When we parted he begged me not to give any information concerning him to any military party I might chance to meet upon his track; and certainly for his youth's sake, and for the courage displayed in that bold adventure of a solitary flight across this hundred miles of desert, I did wish for him a clean escape, fugitive that he was.

Twenty-four hours later this other adventurer had accomplished his undertaking; the desert had been crossed, and he sauntered leisurely and content under the cottonwoods and tall willows that make up the forests of the lower Colorado valley. It was only the twenty-second day of February, but the cottonwood trees were in full leaf and gave delightful shade. The willows, though they had not yet divested themselves of more than half their last year's foliage, were in flower. The yellow catkins were actually crowding off the leaves which had kept their places and retained their freshness during the brief frostless winter.

This belt of riverside timber is occupied by the Yuma Indians; but from the roadside no dwellings of the aborigines were apparent. One saw, however, numerous pathways which had been. cut through the dense thickets leading from the road to the villages, and the voices of Indian children at their sports came ringing out from the deep shady distance. On gaining the open river bank, I saw, near the ferry, four stalwart Yumas, in their usual picturesque costume of a red and yellow striped breech cloth, lying fast asleep on the upturned bottom of an abandoned flat boat. I disturbed not their slumbers. Two Mexicans near

by interested me more; for they, observant of my approach, stood holding the oars of their rude skiff, eager to earn "dos reales' by transferring me to the opposite bank. I was not unwilling to avail myself of their services. Once on the Arizona side of the river, an hour's walk would bring me to the thriving little town of Yuma, and my five days on the desert had well prepared me to appreciate the comforts of a well kept village hotel and the society of the civilized.

:0:

THE METHOD OF DISTINGUISHING

IT

SPECIES OF

POPULUS AND JUGLANS BY THE YOUNG

NAKED BRANCHES.1

BY PROF. W. J. BEAL.

T is supposed to be the aim of the botanist when he describes a plant to name the peculiarities which are the most striking and constant, especially those which are easily seen with the unassisted eye. The writer has often been surprised that the peculiarities of the pith, bark, leaf scars and buds of our deciduous leaved trees and shrubs are not more frequently given in descriptions.

For five or six months of each year most of these plants are destitute of flowers, fruit or leaves. If it is easy or possible to distinguish species by the points above named, it certainly would often be very convenient. In 1876, Frederick Brendel, of Peoria, Illinois, said: "We have no surer guide than the characters taken from the arrangement, form and construction of the buds, and in many cases from the leaf scars."

I will now proceed to point out some of the differences between the species of Populus and of Juglans, as seen when the young growth is destitute of foliage. I have studied four species of Populus and two of Juglans, all natives of Michigan.

Populus tremuloides.-In very slender branches one year old all of the pith is green; in larger branches a green layer surrounds the pith, which is of a whitish color much resembling the wood. With a short exposure to the air the pith becomes brown,

The bud scales are polished. The transverse diameter of the

1 Read at the Boston meeting of the American Association for the Advancement of Science, Aug., 1880.

2 Bulletin of the Illinois Museum of Natural History, No. 1, page 26.