127 



This perhaps is the proper place to notice one feature of the Collectanea, hy which 

 its value to all who feel an interest in the geographical distribution of British plants 

 is greatly increased. " At the foot of the page, and under a line, a (ew species are in- 

 troduced as being, from their ascertained range in Britain, likely to form early addi- 

 tions to the Flora of Moray. It is on this account, and with the view of noting their 

 localities in the adjoining districts, that they have been placed here. A comparison, 

 however, of Lists T. and II. will show the plants, which are most probably undisco- 

 vered denizens, as they contain the species found on either side, but not yet within the 

 Province." — Pref. v. The lists referred to are : — 



" I. — List of Plants, not nbserned in Moray, but found in Aberdeenshire, or in the 

 eastern part of Banffshire." This List contains 89 species. 



" II. — List of Plants not observed in Moral/, but found on the west side of Scotland 

 and north of Oban and lona, or in the counties north of the Caledonian Canal." Con- 

 taining 69 species, 17 of which are common to both lists. Two other lists are also 

 given ; one of QQ species, not uncommon within sixteen miles of Edinburgh, but either 

 not observed or very rare in Moray ; and the other of 42 species of Moray plants which 

 are not found within sixteen miles of Edinburgh. 



With regard to the fourth rule, the omission of the times of flowering is perhaps 

 of little importance, although they would have formed an interesting addition to the 

 Collectanea ; but we confess that we should have been glad to see some notice of the 

 geological relations of the species growing in the district. On this subject the com- 

 piler observes : — 



" In such a treatise as this, it is usual to give a sketch of the geological structure 

 of the district. Such would have been attempted, had there been a sufl5cient number 

 of facts ascertained to show that there was here really any connexion between the ve- 

 getation and the underlying formations. The distance from the shore, and the ele- 

 vation above the sea level, seem to influence the distribution of the species far more 

 than the mineralogical character of the strata over which they grow. Besides, through- 

 out the Province generally, and especially in the lower part of it, there is such a vast 

 accumulation of alluvial matter interposed between the rock and soil, that the nature 

 of the latter and of its vegetation depends mainly upon the circumstance of the allu- 

 vial deposits or subsoil being mossy, gravelly or clayey. In a few spots within the 

 Province, such as Craighalkie near Tomintoul, where the beds of limestone, subordi- 

 nate to the primary stratified fonnations, crop out, there are occasionally to be found 

 several species of plants, whose range is evidently circumscribed within the influence 

 of the calcareous soil. Avena jwatensis seems confined to soils of this nature, changing 

 its habit as the proportion of their ingredients diff'ers. Where there is a superab\m- 

 dance of limy matter the plant often assumes a glaucous and rigid appearance, which 

 has probably originated the A. alpina, and causes it still to hold a place as a distinct 

 species." — Pref. iv. 



In the above extract there is much to confinn our own views respecting the geolo- 

 gical distribution of plants. We are of opinion that it is by the surface soil in which 

 they grow that plants are aff'ected, and not by the rocks or strata ovei- which they occur, 

 unless the latter happen to lie so near the surface as to aff'ect the surface soil, by altering 

 its constituent parts or modifying their proportions. We have no doubt that elevation 

 has considerable influence in the distribution of species ; but we cannot help suspecting 

 that the character of the soil of a given district exercises quite as powerful an influence. 

 Avena pratensis and alpina mentioned above, confirm the truth of our position. These 



