SECT. I 



CRYPTOGAMS 



417 



the first to be discovered. They live as saprophytes and have the form 

 of whitish, subterranean tubers which bear the sexual organs on their 

 upper surface. In the case of L. inundatum they are found on damp peaty 

 soil, and in the tropical L. cernuum, with erect profusely-branched shoots, 

 the prothallia are almost devoid of chlorophyll and are attached to the 

 soil by rhizoids ; they have the form of small, half-buried, cushion-like 



Fig. 349. — Lycopodium clavatim. 1, Plant with fertile shoots ; 2, scale-like sporophyll with 

 sporangium ; 3, spores, highly magnified. (After Wossidlo. Officinal.) 



masses of tissue which give rise to green aerial thalloid lobes. The 

 archegonia occur at the base of these lobes, the antheridia on 

 their surface. The antheridia are somewhat sunk in the tissue (Fig. 

 350, C), and enclose numerous spermatozoid mother -cells, in which 

 small biciliate spermatozoids are formed. The archegonia (Fig. 

 350, D) are constructed like those of the Ferns, but have a shorter 



2 F 



