DR. NYLANDER ON GONIDIA AND THEIR DIFFERENT FORMS. 45 
come (by what magical attraction ?), when gonidia are able to 
originate, and indeed do originate, in tlie thallus itself? 
4th. Not a few thalli are entirely cellulose, nourishing gonidia 
(or gonimia) in the cellules, and not having any lichenohyphaB, or 
others having them only sparingly. 
5th. In young propagula of Collemacei we see constantly gonimia 
originating, and lormed before the hyphge. 
6th. In endogenous cephalodia {Solorina crocea^ Stictce) we see 
gonimic strata formed deep in the thallus, according as this is ex- 
])anded; nor in any way could gonimia from the outside be able to 
find an entrance into those thalline recesses. In what way could 
they penetrate the firm cortex ? 
7th, Very numerous parasitic Lichens, apothecia alone occur- 
ring, entirely want hypha3,* and the most certain characters prove 
that these apothecia belong to Lichens. 
Any one whatever of these points suffices to destroy all Schwer- 
denerism ; others, also, might be added, such as the normal intra- 
conceptacular origin of hymenial gonidimia in many of the 
Pyrenocarpei. Thus from every side there falls to pieces an 
hypothesis informal and absurd, supported by no serious observa- 
tions. 
II. — Different Forms of Gonidia. 
The name gonidia employed in a general sense comprehends 
both gonidia in the stricter sense (or eugonidia') and gonimia (or 
granular gonima'), between which there is a fundamental distinction. 
1 do not here expound their differences, which have already often 
been treated of by me, and of which I have observed in the 
“ Flora,” 1866, p. 179, as follows : — “Of so great weight do these 
appear to be, that Lichens truly seem to afford as it were two 
parallel series — the one marked out by the gonidia and the other by 
the gonimia in the texture, which different anatomical elements are 
not without a certain biological analogy with the globules of the 
blood in animals, and similarly present absolute characters. The 
Collemacei embrace types in which the gonimic apparatus is pre- 
eminent, and occupies the whole thallus ; but in Nephromia^ 
Pannaria Stictina, &c., the same anatomical apparatus exists, 
though reduced or contracted to a peculiar stratum. It is, how- 
ever, most deserving of notice (and this, indeed, marks out the very 
great weight of the character) that types in these gonimic Lichens 
agree with, and externally are very similar to other types in the 
series of those which have the thallus furnished with gonidia. 
This at the same time holds good of genera and species, so that 
there are gonimic species and genera parallel with gonidic species 
* It may here be observed that sometimes apothecia, especially lecideine, 
are produced upon old dead apothecia and proliferous from the hypothecium 
(these dead apothecia being often caused by the hymenium being eaten 
by snails or larvae). 
