CHAP. III. 
LICHENS. 
229 
not dividing into leaves and stems, but lying horizontally upon 
the ground, and emitting roots from its under surface. The 
organs of reproduction consist, firstly^ of a stalked fungus-like 
receptacle, carrying on its apex a calyptra, and bearing thecce. 
on its under side ; secondly^ of a stalked receptacle, plane on 
the upper surface, with oblong bodies imbedded- vertically in 
the disk, and called anthers ; thirdly^ " of little open cups 
(cystul(B), sessile on the upper surface of the fronds, and con- 
taining minute green bodies [gemmce)^ which have the power 
of producing new plants." The first kind is usually con- 
sidered a female flower, its sporules intermixed with elaters : 
the second male, and the third viviparous apparatus. In 
the opinion of many modern botanists, the granules of both 
the two first are sporules : about the function of the last there 
is no difference of opinion. Mirbel considers the first to be 
male and female ; but it must be confessed that in structure 
there is but little analogy between them and the organs of 
more perfect plants. 
In Anthoceros, while the vegetation is the same as in Mar- 
chantia, the organs of reproduction are very different. They 
consist of a subulate column, issuing from a perichsetium 
perpendicular to the frond, and opening halfway into two 
valves, which discover, upon opening, a subulate columella, 
to which sporules are attached without any elaters. There 
are also cystulae upon the frond, in which are enclosed pedi- 
cellate, reticulated bodies, called anthers. 
Sphcerocarpus consists of a delicate roundish frond, on the 
surface of which are clustered several cystulae, each of which 
contains a transparent spherule filled with sporules. 
In Riccia the spherules are not surrounded by cystulae, but 
immersed in the substance of the frond. 
7. Lichens. 
These have a lobed frond or thallus, the inner substance 
of which consists wholly of reproductive matter, that breaks 
through the upper surface in certain forms, which have 
been called fructification. These forms are twofold ; firstly, 
shields or scutella, which are little coloured cups or lines with 
a hard disk, surrounded by a rim, and containing asci, or 
Q 3 
