especially as the word was understood and applied by Platearius, Brunfels, Tragus, Lobel, and C. Bauhin, with no reference to the plants of Columna. They observe that Lobel and Tabernæmontanus give three figures but fail to show in what respect these forms differ. They make an advance in being inclined to reduce these three forms to a single species, without, however, giving any definite reason for so doing. A single figure of a fruiting Marchantia, resembling that of Fuchsius is appended. Why the Lichens of Columna are passed over in silence in a "Historia Universalis" is not clear. The authors could not have been ignorant of the work of Columna, for his hepatics or lichens," as we have seen, find a place in the Pinax of C. Bauhin, which they quote. 66 In the years intervening between the brothers Bauhin and John Ray, there appeared three scientific works of varying degrees of importance, to each of which Lindberg traces the first description of a single hepatic. I have not had access to these three works and am thus indebted to Lindberg for my knowledge of their treatment of the Hepatica. The first of these was the "Pinax Rerum Naturalium Brittanicarum " of Chr. Merritt (London, 1667) in which is described a Lichen capillaceus identified by Lindberg as Anthoceros punctatus. In the historically well-known "Anatome Plantarum " of Malpighi are figures and description of Lunularia vulgaris, and, according to Lindberg, there may be found also in the second volume of Sibbald's "Scotia Illustrata" (Edinburgh, 1684) a figure and short diagnosis of Plagiochila asplenoides. During this century the compound microscope had come into use, and we have now entered upon an era of more exact knowledge of the structure and affinities of the lower plants. This advance becomes very evident in the works of that botanist and philosopher, John Ray. Book third of the first volume of his "Historia Plantarum "8 is "about herbs with very minute seeds, flower either none or imper7London; vol. II, 1679. 8 London; vol. I, 1686. fect." "We divide this book," he says, " into two parts. The first will be concerned with stem-bearing herbs of this kind, the second with those wanting a stem and having hypophyllous seeds. These, moreover, are deservedly placed next to the preceding [fungi, algæ, sterile mosses, etc.], which are imperfect and destitute of seed, because these plants themselves were considered sterile and seedless not so long ago—before their seeds came into view by the assistance of the microscope." In the introduction to Part I., "concerning stem-bearing plants," he remarks: "Some species of Lichens do not produce caulicles, but their seeds arise in the leaves themselves, now in a lower, now in an upper part, which, nevertheless, we have thought ought not to be separated from the rest on this account, inasmuch as they agree in all the other known characters." OBSERVATIONS ON THE COMPOSITE.-VIII. The discussion of "Aplopappus," now for some months interrupted, may be conveniently resumed after the recording of some observations upon certain types that were never referred to that genus. In maritime subtropical North America, and to be more definite, on opposite shores of the Gulf of Mexico, grow two species of shrubby or suffrutescent plants, both of which have been referred by many botanists to Solidago. The one inhabiting the northerly and continental shore is Solidago pauciflosculosa, Michx. That of the opposite and insular stations is S. Domingensis, Spreng. The two are so much alike in general appearance that almost any botanist, even a specialist in the field of the Compositæ, if he were to trust his eyesight unaided by a lens, would quite possibly pro nounce the hebarium specimens of them to be all of a single species. But a lens reveals a marked difference in the superficial anatomy of the leaves, and a slight difference in the achenes, but this is all. That they are two excellent species of one genus, is likely to be the opinion of as many botanists as may be able to consider the question with unbiased mind; unless, perchance, a time shall come when histological characters, such as the inner structure of leaves, shall be deemed sufficient for the distinguishing of genera in default of any difference in flower or fruit. I enter this proviso here, because the venulation of the leaf-surfaces in these two plants is remarkably different, though neither in habit or peculiarities of floral structure, or character of fruit can anything more than specific differences be found. These two subtropic maritime shrubs were, I think, never received as very welcome accessions to Solidago; and each of them has in turn been made the type of a distinct genus; and both the men who have thus dealt with one or both the plants were botanists of note and something of specialists in the Compositæ. Nuttall, who founded CHRYSOMA on the first species, did not know the second. Asa Gray, who knew both, suppressed CHRYSOMA by remanding its type to Solidago, and then elevated the second to the rank of a new genus under the name of Gundlachia! And this is not the worst of it. There is rather a classic sheet of herbarium specimens of " Gundlachia" which, both at the time of his publishing that synonym, and afterwards in the Synoptical Flora, he mistook for the other species, that is, for Solidago pauciflosculosa. It will be seen, by reference to the Synoptical Flora, that S. pauciflosculosa is credited to the Bahama Islands; but the sheet of specimens which furnished the author with his only basis for this statement is surely a sheet of "Gundlachia." I shall speak of these specimens again. As I have intimated in an earlier article,' Solidago must stand upon its habit and inflorescence. If these be not 1ERYTHEA, i. 56. deemed sufficient to sustain it in generic rank, then it must go-as Dr. Kuntze says it must anyhow go-into Aster. No shrubs with cymose-corymbose inflorescence-probably no plants of any mode of growth with flat-topped inflorescence -are to be received into Solidago. Indeed, there are genera in plenty, belonging to other orders, which are distinguished by all botanists, on the ground of inflorescence alone. And these two shrubs of the Asteroideæ, so far out of harmony with the great body of Solidago species, must be admitted as the type of a genus, the name of which, by undisputed right of priority is CHRYSOMA; and the most genuine species are those now to be indicated. 1. C. pauciflosculosa. Solidago pauciflosculosa, Michx. Fl. ii. 116 (1803); Torr. & Gray, Fl. ii. 225; Gray, Syn. Fl. 161, in part, excluding the plant of the Bahamas. Chrysoma solidaginoides, Nutt. Journ. Philad. Acad. vii. 67 (1834) and Trans. Am. Phil. Soc. vii. 325. Aster pauciflosculosus, O. Ktze. Rev. Gen. 318 (1891). The most pronounced character of this species, as compared with the next, is the remarkable almost favose reticulation of the surface of the leaves. The only suggestions of an approach to this reticulation I find in some species of another set of maritime or subsaline shrubs, the Isocomas; but Isocoma is remarkably distinct from Chrysoma in the form of its corollas, and the characters of its achene and pappus. But the two genera must surely be looked upon as nearly related. 2. C. Domingensis. Solidago Domingensis, Spreng. Syst. iii. 369 (1826). Gundlachia Domingensis, Gray. Proc. Am. Acad. xvi. 100 (1880). More decidedly shrubby than the preceding; leaves acute, devoid of reticulation: rays white: achenes with little pubescence. Var. obtusifolia. Apparently only suffrutescent: leaves narrowly oblanceolate, obtuse. Plant of the Bahama Islands. From the genus Solidago as he limited it, these West Indian plants that make Asa Gray's Gundlachia are in no wise to be distinguished. They have, indeed, white rays; but so has S. bicolor, which he did not remove from Solidago. And yet, the white rays were what he seemed to emphasize as the generic character. But he also mentions the shrubby habit and subcorymbose inflorescence as distinguishing marks; and in these respects, as I have said, Gundlachia is quite like one of the species that he left in Solidago; so very like it that, without a lens, he could not, in the herbarium, distinguish it from that species of "Solidago." But it is here worth recording that very early in his botanical career he did perceive and admit that the West Indian plant is congeneric with CHRYSOMA. On a sheet of specimens which, in 1840, he saw in the herbarium of Sir William Hooker-the sheet that is typical for my var. obtusifolia-he wrote: "This belongs to the section Chrysoma and is very nearly allied to S. pauciflosculosa, Michx. Is it not the S. Domingensis, Spreng.?-A. G." Doubtless in that early day when he had a reputation to make, he had examined his plant, and had perceived that it was not actually S. pauciflosculosa. But more than forty years afterwards, and one year subsequently to the proposing of Gundlachia, he wrote upon the same herbarium sheet, under his former note: "It is S. (Chrysoma, Nutt.) pauciflosculosa, Michx.-A. GRAY, 1881,” thus reversing his earlier and right judgment upon these specimens. I can only suppose that in 1881 he looked at them but casually, and without a lens, and that so he was deceived by the mere general aspect and the outline of the leaves, which outline in these Bahama specimens is precisely that of C. pauciflosculosa, though they bear not the faintest suggestion of that remarkable reticulation which marks so distinctly every part of the leaf in this species of the United States mainland. The shrubs thus brought into juxtaposition under the name Chrysoma have their nearest relatives on the Pacific side of the continent, and these are partly maritime and partly montane in their distribution. Only one of them has been named as a Solidago by any author. Two others are |