Where the student reads German, the original is to be preferred, as it is much more complete than the translations, which are made from an abridgment of the original work. This book and the next (7 and 8) are laboratory manuals, and are largely devoted to methods of work.

For identifying plants the following books may be mentioned:—

FOOTNOTES.

[1] For the mounting of permanent preparations, see [Chapter XIX].

[2] The term “colony” is, perhaps, inappropriate, as the whole mass of cells arises from a single one, and may properly be looked upon as an individual plant.

[3] Algæ (sing. alga).

[4] “Host,” the plant or animal upon which a parasite lives.