ches that the green matter originally
arises within the primary chlorophyll- or phycochrom-bearing cellule,
and consequently is not intruded from any external quarter, nor arises
in any way from any parasitism of any kind. The cellule at first is
observed to be empty, and then, by the aid of secretion, green matter
is gradually produced in the cavity and assumes a definite form. It
can, therefore, be very easily and evidently demonstrated that the
origin of green matter in lichens is entirely the same as in other
plants." On another occasion, and in another place, the same eminent
lichenologist remarks,[N] as to the supposed algoid nature of
gonidia--"that such an unnatural existence as they would thus pass,
enclosed in a prison and deprived of all autonomous liberty, is not
at all consonant with the manner of existence of the other algae, and
that it has no parallel in nature, for nothing physiologically
analogous occurs anywhere else. Krempelhuber has argued that there are
no conclusive reasons against the assumption that the lichen-gonidia
may be self-developed organs of the lichen proper rather than algae,
and that these gonidia can continue to vegetate separately, and so be
mistaken for unicellular algae." In this Th. Fries seems substantially
to concur. But there is one strong argument, or rather a repetition of
an argument already cited, placed in a much stronger light, which is
employed by Nylander in the following words:--"So far are what are
called algae, according to the turbid hypothesis of Schwendener, from
constituting true algae, that on the contrary it may be affirmed that
they have a lichenose nature, whence it follows that these pseudo-algae
are in a systematic arrangement to be referred rather to the lichens,
and that the class of algae hitherto so vaguely limited should be
circumscribed by new and truer limits."

As to another phase in this question, there are, as Krempelhuber
remarks, species of lichens which in many countries do not fructify,
and whose propagation can only be carried on by means of the soredia,
and the hyphae of such could in themselves alone no more serve for
propagation than the hyphae from the pileus or stalk of an Agaric,
while it is highly improbable that they could acquire this faculty by
interposition of a foreign algal. On the other hand he argues: "It is
much more conformable to nature that the gonidia, as self-developed
organs of the lichens, should, like the spores, enab