16 
INTRODUCTION. 
L. inundatum, being at all frequent in the low counties of the south-east of 
England, and decreasing in abundance towards the northern and hilly counties ; 
whilst all the rest prevail in the Scottish Highlands, and decrease in frequency in 
a southward course.” — Mr. Watson's MS. 
VIRTUES. — Seldom used in medicine, where safer drugs are attainable. 
The Orkney Islanders use L. selago and clavatum as a cattle remedy ; it is said 
to cure sheep of vermin and of different cutaneous disorders ; in the human 
subject it is an emetic and purgative. The pollen is highly inflammable, and 
was once imported in some abundance from Germany and Sweden to imitate 
lightning at the theatres, but latterly powdered rosin has been substituted. 
Lycopodium clavatum is said to be valuable in dyeing woollen cloths, and for 
making mats it is admirable ; and the Poles make a decoction of its leaves as a 
remedy for the disorder called Plica polonica. The pollen is wetted with so much 
difficulty that when spread on the top of the water in a basin, a finger may be 
plunged to the bottom without becoming wet. 
EQUISETACEiE. 
( Comprises only Equisetum.) 
EauisETACE.®, Decan., Ay., Kau/f., Lind., Hook., Grev., Brong .; — Gonopte- 
rideSj Willd. ; — Part of Filices, Miscellanea, &c., of Authors. 
CLASS. — These plants differ widely from all those hitherto described, and 
certainly approach very much nearer to flowering plants than Ferns themselves. 
In fact their relation to the Coniferse is so strong, both in external and internal 
structure, and their analogy with some other orders so apparent, that I continue 
them among the Fern allies more in accordance with the opinion of others than 
my own. Yet I cannot consider them Dicotyledonous plants, as Professor Lindley 
has done, because their germination is essentially like that of the Cellulares, and 
their reproductive organs have no analogy with those of flowering plants. In 
fact, Equisetum forms a perfectly distinct order, and cannot be allied with any 
other. 
STRUCTURE. — The stems, which are partly beneath and partly above the 
surface of the ground, are when young filled with very loose cellular tissue : 
the moisture of this soon drying up, they become hollow. They are set at 
intervals with joints, attended by toothed sheaths, are regularly channelled 
or striated, rigid, and covered with fine particles of silex, particularly at the 
ridges of the strise. The depressed part of each channel has two longitudinal 
rows of minute holes or open pores, very different from the usual stomata.', and 
much resembling the pores which Dr. Mohl, of Munich, represents as occurring 
in the woody tissue of the Conifer*, now a well-known characteristic of that 
