le the hyphae
proceeding from them to propagate the individual."[O]

A case in point has been adduced[P] in which gonidia were produced by
the hypha, and the genus _Emericella_,[Q] which is allied to _Husseia_
in the _Trichogastres_, shows a structure in the stem exactly
resembling _Palmella botryoides_ of Greville, and to what occurs in
_Synalyssa_. _Emericella_, with one or two other genera, must,
however, be considered as connecting _Trichogastres_ with lichens, and
the question cannot be considered as satisfactorily decided till a
series of experiments has been made on the germination of lichen
spores and their relation to free algae considered identical with
gonidia. Mr. Thwaites was the first to point out[R] the relation of
the gonidia in the different sections of lichens to different types of
supposed algae. The question cannot be settled by mere _a priori_
notions. It is, perhaps, worthy of remark that in _Chionyphe Carteri_
the threads grow over the cysts exactly as the hypha of lichens is
represented as growing over the gonidia.

Recently, Dr. Thwaites has communicated his views on one phase of this
controversy,[S] which will serve to illustrate the question as seen
from the mycological side. As is well known, this writer has had
considerable experience in the study of the anatomy and physiology of
all the lower cryptogamia, and any suggestion of his on such a subject
will at least commend itself to a patient consideration.

"According to our experience," he writes, "I think parasitic fungi
invariably produce a sad effect upon the tissues they fix themselves
upon or in. These tissues become pale in colour, and in every respect
sickly in appearance. But who has ever seen the gonidia of lichens the
worse for having the 'hypha' growing amongst them? These gonidia are
always in the plumpest state, and with the freshest, healthiest colour
possible. Cannot it enter into the heads of these most patient and
excellent observers, that a cryptogamic plant may have two kinds of
tissue growing side by side, without the necessity of one being
parasitic upon the other, just as one of the higher plants may have
half a dozen kinds of tissue making up its organization? The
beautifully symmetrical growth of the same lichens has seemed to me a
sufficient argument against one portion being parasitic upon another,
but when we see all harmony and robust health, the idea that one
portion is subsisting parasitically upon another ap