82f' 



TABLE sizes*' In tne large genus Selaginella the leaves are of two 



CASE sizes? v^i^y small, and all arranged in one plane on the stem ; 



^ ,, in Zyoe^e;?, an aquatic genus, the leaves form a dense rosette, 



and resemble a quill in form, hence the popular name 



QUILLWORTS. 



A specimen of the Hygrometric Club-xM03S {Selaginella 

 lepidophylla, Spreug.) from Mexico is shown. It spreads 

 out in a flat rosette when wet and closes up into a ball Avhen 

 dry. 



A diagram illustrating the structure of JSelaginella helvetica, 

 Spreiig., is shown on the wall of the descent staircase. 



TABLE Horse-tail Order {Equisetace(p), Perennial, ter- 

 CASE restrial, or aquatic plants with subterranean rhizomes and 

 B. straight, jointed stems bearing whorls of leaves. Owing to 

 the presence of a large amount of silica, the .stems are so 

 rough that they are used to polish wood, and even rnetals. 

 The fruit forms a cone at the tip of the stem, and in some 

 species is produced on special, fertile, branchless stems, 

 destitute of green colour. 



Calamites is a fossil form of this order tliat attained a large 

 size during the Carboniferous period. Some specimens are 

 exhibited. 



Several species of -E'5^?«W«<wi occur in this country, but the 

 best known for its economic nses \9 Equisetum hycmal€,'L., 

 * which is also found in otlier parts of Europe, North Africa, 



North Asia, and North America. 



No. 211. Rings of Dutch EusHEs'the twisted stems of 

 E. hyemale known as Asfrella in Pavia where they are sold 

 at one halfpenny for 12 rings and used for cleaning wooden 

 spoons, platters, &c- 



■ A sample of the chopped stems of this species as used in 

 medicine in North China is shown in the lower division of 

 this case. Near this is a mounted specimen of E. gigantcum, L., 

 from Rio Janeiro, and in the upper part of the case observe 

 stems of E. sylvaticum^ L., used at Munich for cleaning 

 pewter, also fine mounted specimens of plants of E. Telmateia, 

 Lam., from near Bonsall, Derbyshire. A diagram showing 

 structure of this species is shown on the wall of the descent 

 staircase. 



,Pill"WOrt Order {Rhizocarpefp). Aquatic, or growing 

 in damp places, mostly native^ of warm regions. Spoiangia 

 are of two sizes. 



