434 ILLUSTRATION OF THE BOTANY OF [ Musci. 
covering with beautiful verdure the driest rocks, the barks of trees, or the surface of 
the ground. They are, however, abundant only in temperate climates, where there is 
some degree of atmospheric moisture : they are also found, but in less variety, within 
the tropics, notwithstanding the degree of moisture ; hence it may be inferred, that it 
is the heat of such situations which is injurious to their prevalence: -their absence, 
therefore, from the hot and dry parts of India, as well as of the world, might be 
expected, as heat, unaccompanied by moisture, is there usually so greatly in excess 
to what is congenial to their habits. 
The Muscology of India has been little investigated: none are noticed in Dr. Rox- 
burgh’s Flora Indica ; 113 species are enumerated in Dr. Wallich’s Catalogue, chiefly 
from Nepal. In the author’s collection there are only fifty-five species, almost all from 
one locality, that is, Mussooree: of these, several are the same as those in the East- 
Indian Herbarium, but others are peculiar to the author’s collection, though all are 
not new species, being for the most part such as are also found in Great Britain, and 
other parts of Europe. Mr. Griffith, when in Assam, paid considerable attention to the 
Mosses he found in his journey. The results he has detailed in a paper read before the 
Linnzan Society, but which, not having yet been published, I can only refer to 
its abstract in the proceedings of the Society. Most of the species were “ gathered 
in the Khasya Hills, an elevated tract of country, forming part of the eastern frontier 
of British India. The climate is described to be excessively moist, which will account 
for the large number of JJosses collected in the journey by Mr. Griffith, forming about 
one-eighth of the entire family, 1324 being the amount of species enumerated by Bridel, 
in his Bryologia Universa.” 
The Mosses in Dr. Wallich’s and my own collection, have had the advantage of being 
examined, and named, by Sir Wm. Jackson Hooker, whose determinations, from his 
great knowledge of the subject, and possessing one of the most extensive Herbaria, are 
of the greatest value, and worthy the entire confidence of botanists. From his investi- 
gations, therefore, we find that in the hot parts of India, and places to its south, such 
as the Malayan Peninsula, Penang, and Singapore, where there is also moisture, species 
of the genera Syrrhopodon, Octoblepharum, and Hyophila, have been obtained; and, 
excepting of the last, solitary species, of such genera as Trichostomum, Tortula, Dicra- 
num, Bryum, and Hypnum. Of these, Tortula indica is found on walls near Calcutta, 
_ Dicranum megalophyllum, Brid., in Singapore, Hypnum Tavoyense in Tavoy, with H. retro- 
— flerum, and microcarpum,in Ava. Bryum acuminatum, Hook., in Penang, and the West- 
Indies. Octoblepharum albidum, Hedw., in Singapore, also in the West-Indies, S. Ame- 
rica, Mauritius, and Madagascar. Hypnum spiniforme, Hedw., at Penang, in Mau- 
‘Titius, the Cape of Good Hope, and the West-Indies. Of the genera of tropical situ- 
ations, of which species extend into Nepal and the mountains, we may mention 
Syrrhopodon, Calymperes, Schiotheimia, and Pterogonium. Orthodon is common to Nepal 
and the Isle of Bourbon, the same species, O. serratus, occurring in both. Sclero- 
dontum, found in Brazil and New Holland, has also a species, S. secundum, in the 
Himalayas, 
