often has had two or more related species under his eye when describing the one to which he gave recognition and a name, and herbarium study calls for some discriminating power; but notwithstanding the inherent difficulties, its value is real and lasting. Though the founder of the Missouri Botanical Garden did not specifically mention a herbarium in his will, his purchase of the Bernhardi collection in the early years of his planning shows his practical appreciation of the need of such a part of the equipment of the institution, and in some manuscript suggestions for his trustees, not made a part of his will, he distinctly states that the correct naming of the plants cultivated in an educational and research garden 'can only be done by a botanist, aided by an herbarium and botanic library'; and one of the world's greatest botanists, in speaking of the relative value of living collections and the hortus siccus or herbarium, expresses himself as follows:[1] "If the collections of dried plants are compared with those of living plants, the advantages of each are more nearly balanced than is usually thought. In a herbarium you see simultaneously specimens of related species and also different localities, different ages or different conditions of the same species. You know the name of the plant, if the herbarium is well determined, and you go at once to the authors who have spoken of it. You learn its origin, which is indicated on the label. On its side, the living plant gives more means for certain anatomical observations. It permits one to better describe certain characters of little importance, such as color, odor, etc., but in the country the plants are not named, and in a botanical garden they are often badly named. . . . The geographic origin of the plants is there almost always uncertain or unknown; the individuals are often modified by cultivation and crossing; fruits are rarely seen with the flowers; rarely several individuals of the same species or several related species; and still more rarely are botanists permitted to gather enough specimens of an exotic plant to examine it to their satisfaction and to preserve the proofs of their work." And he goes so far as to head the chapter devoted to this consideration with the lines: 'Of herbaria in general and of their superiority to every other zoological or botanical collection.' It might have been added, truthfully, that in a garden the representation of any given species is likely to be transient, since the casualties to which living specimens are liable are innumerable; on the other hand, the specimens in the herbarium, though subject to their own particular dangers, are far less likely to suffer, and rarely disappear even in the course of very long periods of time except as a result of gross carelessness.
The principal collections of this class at the Missouri Botanical Garden are, in the first place, the herbarium of Engelmann, which,
- ↑ De Candolle, La Phytographie, p. 365.
