n, "Handbuch der Allgemeinen
Mykologie" (1851).

VII.

GERMINATION AND GROWTH.

In describing the structure of these organisms in a previous
chapter, the modes of germination and growth from the spores have
been purposely excluded and reserved for the present. It may be
assumed that the reader, having followed us to this point, is
prepared for our observations by some knowledge of the chief features
of structure in the principal groups, and of the main distinctions
in the classification, or at least sufficient to obviate any
repetition here. In very many species it is by no means difficult to
induce germination of the spores, whilst in others success is by no
means certain.

M. de Seynes made the _Hymenomycetes_ an especial object of study,[A]
but he can give us no information on the germination and growth of the
spore. Hitherto almost nothing is positively known. As to the form of
the spore, it is always at first spherical, which it retains for a
long time, while attached to the basidia, and in some species, but
rarely, this form is final, as in _Ag. terreus_, &c. The most usual
form is either ovoid or regularly elliptic. All the _Coprini_ have the
spores oval, ovoid, more or less elongated or attenuated from the
hilum, which is more translucent than the rest of the spore. This last
form is rather general amongst the Leucospores, in _Amanita_,
_Lepiota_, &c. At other times the spores are fusiform, with regularly
attenuated extremities, as in _Ag. ermineus_, Fr., or with obtuse
extremities, as in _Ag. rutilans_, Sch. In _Hygrophorus_ they are
rather irregular, reniform, or compressed in the centre all round.
Hoffmann[B] has given a figure taken from _Ag. chlorophanus_, and
Seynes verified it upon _Ag. ceraceus_, Sow. (See figures on page
121.)

The exospore is sometimes roughened, with more or less projecting
warts, as may be seen in _Russula_, which much resembles _Lactarius_
in this as in some other particulars. The spores of the _Dermini_ and
the _Hyporhodii_ often differ much from the sphaerical form. In _Ag.
pluteus_, Fr., and _Ag. phaiocephalus_, Bull, there is already a
commencement of the polygonal form, but the angles are much rounded.
It is in _Ag. sericeus_, _Ag. rubellus_, &c., that the polygonal form
becomes most distinct. In _Dermini_ the angles are more or less
pronounced, and become rather acute in _Ag. murinus_, Sow., and _Ag.
ramosus_, Bull. The passage from one to the other may