188 
OF THE HERBARIUM. 
material from different localities, embracing widely-sepa- 
rated areas. 
The more numerous the localities represented in an her- 
barium are, the more valuable is it in the eyes of the man 
of science. For the same reason he should bring together, 
in the case of the Phanerogamia, not only flowers, but ripe 
fruit, both with and without the capsule, or, if the plants are 
dioecious, examples of both the sexes ; in the case of the 
Cryptogamia, sterile as well as fertile forms from numerous 
localities, since, in many cases (as for instance among the 
Mosses) peculiarities of situation, hindering or promoting 
the fertility of a plant, influence its habit and character in 
no slight degree. In a word, in each order of plants, the 
collector should endeavour to obtain the successive stages 
of development, if he intends to study them thoroughly, and 
to give a scientific value to his collection. 
That he may study the specimens with ease, his herba- 
rium should be so arranged, that he may be able to lay his 
hand at any moment, and without loss of time, on the ex- 
ample he wishes for ; and also be able to take it out and 
replace it without injury to the collection. 
For this, I recommend the following plan. The wrappers 
being laid on a table with their openings looking to the 
left, the whole of the species belonging to a single genus 
(or a section of them, if the genus is very large) is to be 
lifted off the pile, and enclosed in a separate wrapper, the 
opening of which looks to the right. This arrangement 
tends greatly to convenience in handling the specimens, as 
the operator can remove each genus, (or, it may be, portion 
of a genus,) with the greatest ease, and, when properly 
labelled, any desired genus can be got at without disturbing 
the other packets. 
The genera included under an order should next be 
isolated. As a rule, this involves a pile of specimens much 
too bulky to be comprehended within the limits of a single 
wrapper. The better plan, therefore, is to lay the pile be- 
tween two sheets of stout pasteboard of corresponding size, 
