AN INTRODUCTION TO THE STUDY OF LICHENS. 105 
times only one spore, while on the other hand, in minute spored 
species, they are innumerable. The form and colour of the spores 
are very much diversified. They range from globose to fusiform 
and acicular. ‘That is, from round to spindle and needle shape. 
Their colour is from a pale greenish or yellowish tinge, to a dark 
olive or deep brown. 
Composed of these several parts, the apothecium constitutes the 
female organ of the fructification, the spores of which are fecun- 
dated by the minute bodies next to be described ; but how, or in 
what way, this fecundation is affected, has not yet been discovered. 
The fecundating bodies are termed sfermatia. They are very 
minute rod-like, or oval organs, varying in length and breadth; 
and are sometimes bent or curved; they are uncoloured and 
transparent. These organs are produced in small cavities, sunk or 
immersed in the Lichen-thallus ; and opening on its surface by a 
small pore. These cavities or cysts are called spermogones. (Fig. 15). 
They sometimes require a lens to discover them; but, on some thal- 
loidal forms, they are plain and prominent. As, for instance, the 
lacinize of certain Ramalinas, and the fronds of Ricasolia amplissima. 
The interior of the spermogonic cell is composed of a number of 
delicate, elongated filaments, all growing from the walls of the 
vesicle, and at orice projecting and converging into the centre of 
it. These filaments are denominated ster7gmata (Gr. sterigma, 
a prop or support) from the fact that they bear the spermatia. 
The sterigmata are sometimes simple or articulate and branched, 
and they bear the spermatia on their sides or apices. The con- 
tents of the spermogones like those of the apothecia, are truly 
lichenose, being filled and bathed with lichenine. Perhaps, we 
should mention another minute organ found upon the Lichen, and 
named fycuides. ‘These externally resemble spermogones, and only 
a microscopical examination can distinguish them. They differ, 
however, in their internal growth. Instead of sterigmatic filaments, 
