342 LYCOPODIALES 
that the general plan of construction of the prothallus is the same as in 
the LZ. cernuum-type, but modified in accordance with the saprophytic 
method of nutrition. 
arch 
Fic. 179. 
A=old prothallus of Lycopodium annotinum, L., with young plant projecting beyond 
the earth-surface (¢). Natural size. £=median section through a young prothallus of 
Lycopodium clavatum, L.  » about 30. C=part of this from the middle region of the 
upper surface, with antheridia in different stages. 52. M=part of the margin of the 
median section, with meristem and archegonia. 52. ec=the epidermis devoid of 
fungus, with rbizoids ;_ »=cortical layers, with their cells filled by hyphal coils ; =the 
palisade layer, also filled with hyphwe; sf=the storage tissue; 72=the meristem; 
an=anthendia; avch=archegonia; evz=an embryo; /=its foot; wits root. (After 
Bruchmann, from Engler and Prantl.) 
In the third type, exemplified by Z. phlegmaria and other epiphytic 
species, the prothallus is more attenuated, and repeatedly branched. The 
delicate colourless branches extend widely through the dead bark on 
