THE MOSS WOELD. 
373 
continuation of their existence is singularly cared for. In 
Aulacomnium and other mosses we constantly find in place of 
fruit a pseudopodium or naked stalk hearing at the summit a 
globose head of gemmae, and in Orthotrichum Lyellii and 
other species the leaves produce on the surface jointed fila- 
ments, and both these appendages on falling off develope 
prothallium, from which new plants originate. The same 
takes place with tubercles which develope on roots, and thus 
we may strip the rocks of their tenants Grimmia, Rhaco- 
mitrium, Tortula, &c. ; yet a few years suffice to restore 
them from the adhering radicles left behind ; and again 
the caducous ramuli of Campylopus and Leucobryum become 
new plants, while even a single deciduous leaf of Funaria 
hygrometrica has been seen to produce prothallium from its 
basal cells, by which the establishment of a new colony is 
secured. 
Classification. 
The arrangement of mosses is confessedly a subject of great 
difficulty, and one that has occupied the thoughtful attention 
of all Bryological writers. Up to a recent date the peristome 
alone was used as the chief character by which to establish 
genera, and thus species were thrown together which agreed in 
nothing but the number and form of the teeth in this organ ; 
it may be interesting, however, to give an outline of the prin- 
cipal systems that have been proposed. 
1. Hedwig published the first of these in his “Fundamenta 
Muscorum,” 1782, with 25 genera arranged in 3 divisions. 
(1) Without a peristome ( Phascum ). (2) With a naked peri- 
stome ( Sphagnum , Hedwigia , Gymnostomum). (3) With a 
fully-formed peristome, sub-divided into : a. Peristome single 
(11 genera), b. Peristome double (10 genera). 
2. Bridel, in the “Bryologia Universa,” 1826, greatly in- 
creased the number of genera, arranged as follows : — 
Sec. 1. Capsule operculate. 
Class 1. Fruit without a vaginula on a pseudopodium 
( Archidium , Sphagnum). Class 2. Fruit acrocarpous. 
Class 3. Fruit pleurocarpous. Class 4. Fruit radical. 
Class 5. Fruit axillary. Class 6. Fruit under an ac- 
cessory leaf. 
Sec. 2. Capsule cleft (Andreaea). 
3. The next important alteration in system was that adopted 
by C. Muller, in his “ Synopsis Muscorum,” 1 849, in which the 
minute structure of the leaf takes a prominent part in the 
characters of tribes and genera, and many gymnostomous species 
yol. x. — no. xli. c c 
