POTATO 595 " a foode as also a meate for pleasure equall in goodnesse and wholesomenesse unto the same, being either rosted in the embers, or boiled and eaten with oile, vinegar and pepper, or dressed any other way by the hand of some cunning in cookerie." A second edition of the Herbal was published in 1636 by Thomas Johnson, with a different illustration from that given in the first edition, and one which in some respects, as in showing the true nature of the tuber, is superior to the first. The phenomenon of growing out or " super- tuberation " is shown in this cut. Previous to this (in 1629) Parkinson, the friend and associate of Johnson, had published his Paradisus, in which (p. 517) he gives an indifferent figure of the potato under the name of Papas sen Battatas Virginianorum, and adds details as to the method of cooking the tubers which seem to indicate that they were still luxuries rather than necessaries. Chabraeus, who wrote in 1666, tells us that the Peruvians made bread from the tubers, which they called " chunno." He further tells us that by the natives " Virginiese, insulss" the plant was called "openauk," and that it is now known in European gardens, but he makes no mention of its use as an esculent vegetable, and, in deed, includes it among "plantse malignee et venenatae." Heriot (De Bry s Collection of Voyages], in his report on Virginia, describes a plant under the same name "with roots as large as a walnut and others much larger ; they grow in damp soil, many hanging together as if fixed on ropes ; they are good food either boiled or roasted." The plant (which is not a native of Virginia) was probably introduced there in consequence of the intercourse of the early settlers with the Spaniards, who derived the plant from Peru or other parts of South America, and perhaps provisioned their ships with its tubers. In any case the cultivation of the potato in England made but little pro gress, even though it was strongly urged by the Royal Society in 1663; and not much more than a century has elapsed since its cultivation on a large scale became general. The source of the potato being known, it is a matter of interest to determine the particular species from which the cultivated forms have descended and the exact part of the great American continent in which it is indigenous. As to the first point, botanists are agreed that the only species in general cultivation in Great Britain is the one which Bauhin, in his Phytopinax, p. 89 (1596), called Solanum tuberosum esculentum, a name adopted by Linnaeus (omit ting the last epithet), and employed by all botanical writers. This species is native in Chili, but it is very doubtful if it is^ truly wild farther north. Mr Baker (Journal of the Linnean Society, vol. xx., 1884, p. 489) has reviewed the tuber-bearing species of Solanum from a systematic point of view as well as from that of geographical distribution. Out of twenty so-called species he considers six to be really distinct, while the others are merely synonymous or trifling variations. The six admitted tuber -bearing species are S. tuberosum, S. Maglia, S. Commersoni, S. cardiophyllum, S. Jamesii, and S, oxycarpum. S. tuberosum is, according to Mr Baker, a native not only of the Andes of Chili but also of those of Peru, Bolivia, Ecuador and Colombia, also of the mountains of Costa Rica, Mexico, and the south-western United States. It seems most probable, how ever, that some at least of the plants mentioned in the northern part of the American continent have no claim to be considered absolutely wild, but are the descendants of cultivated forms. S. Magha is a native of the Chilian coast as far south as the Chonos Archipelago, and was cultivated in the garden of the Horticultural iety at Chiswick in 1822, being considered by Sabine, in his paper on the native country of the wild potato, to be the true i. tuberosum and the origin of the cultivated forms. This species was also found by Darwin in Chili, and was considered by him, as by habme before him, to be the wild potato. It is remarkable, says Darwin that the same plant should be found in the sterile aountams of central Chili, where a drop of rain does not fall for than six months, and within the damp forests of these southern (Chonos) islands. The explanation, according to Baker, is that the plant of the dry mountains is S. tuberosum, that of the coast is S. Maglia. It must, however, be stated that, although Mr Baker refers to the plants figured by Sabine ( Trans. Hort. Soc. Lond., vol. v. p. 249) as being without doubt S. Maglia, A. do Candolle (Originc dcs Plantes cultivees, p. 40) is equally emphatic in the opinion, " ce qui saute aux yeux," that the plant grown from Chilian tubers and figured in the plate before cited is S. tuberosum. S. Commersoni occurs in Uruguay, Buenos Ayres, and the Argentine Republic, in rocky situations at a low level. Under the name of S. Ohrondii it has lately been introduced into western France, where it is not only hardy but produces abundance of tubers, which are palatable, but have a slightly acid taste. The tubers give promise of improvement under cultivation. S. cardio- phyUum, described by Lindley in the Journal of the Horticultural Society, is a native of the mountains of central Mexico at elevations of 8000 to 9000 feet. S. Jamesii is a well-defined species occurring in the mountains of Colorado, New Mexico, and Arizona, and also in Mexico. In a wild state the tubers are not larger than marbles, but as the plant is now in cultivation in England it may be expected to improve in this particular. S. oxycarpum is stated by Mr Baker to be a little known but very distinct tuberous species from central Mexico. 1 Mr Baker looks upon the forms enumerated not only with the eye of a systematic botanist but with the tendencies of one whose object is to assign varying forms to one common type from which they have, or may probably have, arisen. But from a practical point of view the forms in question require careful analysis rather than synthesis. Their morphological peculiarities and chemical constitution deserve attentive consideration as to their degree of constancy, and more particularly as to any relation that may be traced between them and the climatic circumstances under which they grow naturally, and their power of resistance to the attacks of disease. A review of the localities in which the presence of S. tuberosum and its tuber-bearing allies has been ascertained shows that, broadly, these varieties may be divided into moun tainous and littoral. In either case they would not be subjected, at least in their growing season, to the same extremes of heat, cold, and drought as plants growing on inland plains. Again, those forms growing at a high elevation would probably start into growth later in the season than those near the coast. The significance of these facts from a cultural point of view is twofold : for, while a late variety is desirable for culture in Great Britain, as ensuring more or less immunity from spring frost, which would injure the early sorts, it is, on the other hand, undesirable, because late varieties are more liable to be attacked by the potato disease, which as a rule makes its appearance at or about the time when the earliest varieties are ready for lifting, but before the late varieties are matured, and consequently while they are still exposed to the destructive influences of the fungus. 1 Although these six are the only species admitted as such by Mr Baker, it is well to note some of the forms or varieties, because, although they may not be entitled to specific rank, which after all is a matter of opinion, they may yet be of importance in the future. First of all may be mentioned the S. etuberosum of Lindley, differing from the common S. tuberosum in not producing tubers. This was found in Chili, and is probably not specifically distinct, although exceptional, for it is by no means very unusual to find even cultivated plants pro duce no tubers. S. Fernandezianum is, according to Baker, a form of S. tuberosum, but if so its habitat in the mountain woods of Juan Fernandez is climatically different from that in the dry mountains of central Chili, where, as we have seen, the true S. tuberosum grows. S. otites was found recently by M. Andre on the summit of Quindiu in Colombia, at a height of 11,483 feet, in a rigorous climate, only about 3300 feet below the perpetual snows of Tolima. It produces tubers of the size of a nut. S. Andreanum, found by M. Andre at Cauca, at an elevation of 6234 feet, was considered by the traveller to be the true S. tuberosum, but this view is not shared by Mr Baker, who named it after the discoverer. Its tubers, if it produces any, have not Deen seen. S. immite is probably only a slight variety of S. tuberosum, as are also the Venezuelan S. colombianum, S. verrucosum, S. demissum, and S. utile. S. Fendleri, a native of the mountains of New Mexico and Arizona, was cousidered by Asa Gray to be likewise a form of
S. tuberosum.