18 
INTRODUCTION. 
germinal vesicle contained in the archegouium is fertilized by the active filaments 
developed from the small spores, to become developed into a leafy plant like the 
parent, quickly breaking out at the top of the large spore, and sending a leaf-bud 
upwards, and roots downwards. When these have acquired a certain size the 
remains of the large spore and its contents wither away, but while they remain 
the little plant much resembles a germinating Monocotyledon.* — A. H.] 
DISTRIBUTION.— “The single species of this order, a submerged aquatic, 
can of course grow oidy where there is a suitable home in the waters. Probably 
it may require also that the water be of low temperature in summer, since most 
of its habitats are the Highland lakes ; although, according to Mr. Griffith, it 
extends southward into Shropshire. There are very few other English and Welsh 
counties that produce it, and these few are all mountainous; namely, Caernar- 
vonshire, Denbighshire, Cumberland, and Northumberland. In most counties 
north of the Firths of Forth and Clyde, we may find it in the lakes, some of them 
being situate COO yards or upwards above the sea.” — Mr. Watson’s MS. 
LYCOPODIACEiE. 
( Comprises only Lycopodium.) 
LYCOPODIACEIE, Br., Decan., Hook ., Lindl., Burn. 
LyCOPODIN’E.H, Swz. 
Lycopode.e, Spreny. 
Bivalva, lloffm. 
Valvat.e, Web., Mohr. 
Stachiopterides, Willd. 
[STRUCTURE.— The Lycopodia resemble certain of the Mosses in habit, the 
Ferns in vascular structure and foliaceous texture, and the Isoetacese in fruit. 
The stems are slender, branched by forking, leafy throughout their whole extent, 
not subterranean, but upright or trailing along the ground or climbing, frequently 
to the distance of many feet, and throwing out radicles, wherever they bifurcate. 
A transverse section of the root shows the longitudinal ducts to be collected in the 
axis. In the stem they are similarly arranged, the vessels and ducts in this order 
are ordinarily of the spiral kind. The stomata on the epidermis of the leaves are 
very abundant, the epidermis itself being reticulated, not as in the Ferns,' but into 
regular four-sided meshes. 
Reproduction. The thecae arc sessile, either in the axils of the ordinary 
leaves, or of scales collected into terminal spikes or catkins. Tliev are of one 
kind in most of our species, consisting of kidney-shaped cases filled with minute 
spores, resembling the small spores of Isoetcs. In Lycopodium selaginoides, 
and many fore.gn species, which are now generally separated as a distinct genus, 
under the name of Selaginella, the lower scales of the spikes have larger theca:,' 
«.» cssayon ^ 
with the earlier history of the spores which wYll'i v°I. is, but he was unacquainted 
referred to under Equisetaceie -a! H.’ b ° ,ound 1,1 ,lct,,ll in "'.fmeistcr’s works, 
