CARPOSPOREM. 
a fact first observed by Famintzin and Baranetzky, but incorrectly explained. It is to 
Schwendener's knowledge of the facts, the result of researches extending over many 
years, that the correct interpretation is due in these cases of the relationship borne by the 
Lichen-forming Fungus to the gonidia, i. e. to the Alga which it attacks^ 
After these preliminary remarks the following description will be intelligible to the 
beginner. It is transferred, with but slight alterations, from the first edition of this 
book. We will consider first the Lichen as a whole, as it comes under observation, the 
nourishing Alga being distinguished as an elemental form of the thallus under the name 
Gonidia; and we will afterwards discuss the question of their algal nature more in detail. 
The Phallus of Lichens is commonly developed in the form of incrustations which 
cover stones and the bark of trees, or penetrate between the lamellae of the epidermis of 
woody plants, and then expose only the fructifications above the surface. These Crus- 
taceous Lichens, as they are termed, have become so completely united in their growth 
to their substratum, at least on the under side, that they cannot be detached completely 
from it without injury to the thallus (Fig. 210,^, B, C). The crustaceous Lichen-thallus 
Lichen (slightly magnified) (slightly magnified). 
passes over, through various gradations, into that of the Foliaceous Lichens ; the latter 
forms flake-hke expansions often curled, which can be completely detached from the 
ground, stones, moss, bark, &c. which support them, since they are attached to it only 
in places by a few organs of attachment, the Rbizines. The foliaceous thallus often 
attains considerable dimensions, in the large species of Peltigera and Sticta as much as 
a foot in diameter, and from § to i mm. in thickness, and then generally assumes a 
circular form; at the growing margin it forms rounded indented lobes (Fig. 211 and 
Fig. 213, jB). a third form of the Lichen-thallus, also united with the previous one by 
transitional forms, is shown in the Fruticose Lichens, which are attached only at one spot 
and with a narrow base, and rise from it in the form of small much-branched shrubs. 
The branches of the thallus are either flat and ligulate, like th3 lobes of many foliaceous 
Lichens, or slender and cylindrical (Fig. 213, A). In Cladonia and Stereocaulon we have not 
so much a transition from the foliaceous to the fruticose thallus as a combination of the 
A few additional historical notes will be found at the end of this section. 
