as it appears, withheld from his auditors, lest he should lead them into error. This will explain a note in Professor Giseke's preface, p. 19, which however was printed before his request came to my knowledge; for two very intelligent friends, through whom it was meant to be conveyed, judged it unreasonable to be made, as well as improper to be complied with, and therefore suppressed the message.
I have only to add a few practical remarks on the preparation and use of an Herbarium or Hortus Siccus. The advantages of preserving specimens of plants, as far as it can be done, for examination at all times and seasons, is abundantly obvious. Notwithtanding the multitude of books filled with descriptions and figures of plants, and however ample or perfect such may he, they can teach no more than their authors observed; but when we have the works of Nature before us, we can investigate them for ourselves, pursuing any train of inquiry to its utmost extent, nor are we liable to be misled by the
