GENERAL REMARKS. 377 



to be also remarked that they are generally met with about 

 cultivation, where the natural dryness is remedied by irriga- 

 tion, or in the alpine tracts about places possessing natural 

 sources of water. 



The general proportion they bear to the general flora is 

 small, not exceeding T 1 T the proportion of those of central and 

 western Affghanisthan may be roughly estimated as 

 a proportion to be expected from the extreme dryness, the 

 wants of forests, springs, umbrageous ravines, and dripping 

 rocks. 



It appears to me a remarkable fact, more especially as it 

 obtains to a considerable degree with those from Otipore and 

 Bharowul, that the forms are as decidedly European, as any 

 of those of the Phaenogamous families, although it is precise- 

 ly in this family that a large intermixture might have been 

 looked for, such I take to be illustrated by the occurrence of 

 Timmia, Desmatodon Encalypta, Anictangium, and Phascum, 

 the last of which has only been observed in dry parts of British 

 India. The abundance of Tortula in British India Muscology 

 and a general proportion of the forms of some of the species 

 of Bryum, Weissia, and Gymnostomum Grimmia and all the 

 Orthotrichum. 



No Splachnum or Polytrichum were observed, although 

 some of the localities of Kohi Baba appeared suited to the 

 former, and the country generally to some forms of the latter. 



The areolation appears to me also curious, it is lax at the 

 base and colourless, the green matter makes its appearance as 

 an incrustation along the upper and lower sides or ends of the 

 cells, then it spreads so as to include the sides or septa, gra- 

 dually incroaching so as to leave a small part uncovered. In- 

 deed in the margin in which the incrustation is green, the un- 

 covered part is a mere slit : these cells look like markings on 

 some vessels, the marginal structure is continued into the 

 pilus, where it is much more elongated. Among the Tortulse 

 will be found one which appears to me is remarkable for the 

 appendages to the leaves, of which I only know of instances 



3 A 



