1859.] BRYOLOGY OF THE YORKSHIRE OOLITE. 51 



specimens of each to several distinguislied botanists, "whereby 

 I find that some have considered them distinct species, by- 

 giving to one the appellation of T. Chamcedrys ; the other re- 

 tains its original significant name of T. Seryyllum, from its 

 creeping propensity, rooting and densely covering the ground, 

 often, where it can, to the extent of twenty square feet. One 

 of those Thyme-beds, when in bloom, is a beautiful object. This 

 comes into flower in June, about a month sooner than the other 

 species, and does not remain in flower nearly so long as the other 

 species. It prefers a dry sandy soil, ditch-banks, and rocks; 

 its smell a little aromatic, and has little taste. TJiymus ChaiiKS- 

 drys comes into flower in July, and continues in flower often 

 until late in November. It grows more upright, and in tufts ; 

 a larger plant, a powerful scent, and pungent taste ; not so 

 choice in location as T, Serpyllum ; it may be found grooving most 

 luxuriantly on ant-hills, in old sheep-pastures, in heavy soils, 

 and in northern aspects also, where the other is not found. If 

 the constituents of these plants were analytically obtained, it 

 would most certainly establish their specific claims. 



BRYOLOGY OP THE YORKSHIEE OOLITE. 



On the Bryology of the Oolitic Hills of Yorkshire. A Paper 

 read before Section D, at the meeting of the British Associa- 

 tion at Leeds, September 23, 1858. By ^.H. Davies. 



The subject of the influence exercised by the geological for- 

 mations on the distribution of Mosses, is one which, in con- 

 sequence of the available data being but meagre and unreliable, 

 it would at present be impossible to treat otherwise than vaguely, 

 and the conclusions to be deduced must necessarily be of a crude 

 and unsatisfactory character. 



It will be found, however, that the mechanical (not the che- 

 mical) constitution of the rocks, their comparative dryness or 

 humidity, or — to adopt the terminology of a paper by Mr. Baker, 

 on the subject as relating to the distribution of the higher orders 

 of plants, read before this Section of your Association, at Glas- 

 gow, in 1855 — their " dysgeogenous '^ or " eugeogenous " qua-, 

 lities, very perceptibly influence the dispersion of species. 



