11 . 
well as Botanical knowledge, we are desirous of aiding the efforts of others 
by presenting a sketch of the external features and internal structure of 
the country which has been surveyed. 
It is not merely because of its large geographical area that Yorkshire 
is more rich in vegetable forms than most other English Counties : its 
surface exhibits several distinct characters of soil and stratification, 
accompanied by gradations of elevation, from the sea shore to mountains 
of 2,400 and even 2,600 feet high ; its climate varies accordingly, and 
it lies in such a geographical position as to unite, in a considerable 
degree, the characters of Scottish and English vegetation. 
The mean temperature of York, which is about 50 feet above the sea, 
is very nearly 48° F. and there is little variation in different parts of the 
County, except what unequal elevation above the sea occasions. The 
effect of this on Mickle Fell, the highest mountain in Yorkshire, may be 
estimated at 8° of Fahrenheit, so that the extremes of mean temperature 
in Yorkshire vary from 40° to 48°. From similar data we may state the 
range of highest mean daily temperature, in the shade (in July) at from 
54° to 62°; and the range of lowest mean daily temperature (in January) 
at 25° to 33°. The most prevalent winds are south-easterly, during all 
the year, excepting about a month after the vernal equinox, when, in all 
the eastern parts, north-easterly winds prevail. The quantity of rain 
falling at York is 24 inches, and it is below the average of the County, 
of which the western parts are the most rainy. 
Of 1002 flowering Plants noticed in the following Catalogue, only 
three are peculiar to Yorkshire, viz. 
Arabis hispida— page 13. 
Dryas octopetala — page 38. 
JuNcus poLTCEPHALus — page 109. 
One, not peculiar to the County, flowers no where else in England, viz. 
CoRNus suECicA — page 52. 
Twelve attain in Yorkshire their 
Actsea spicata 
Potentilla fraticosa* 
Rosa sarmentacea 
Sedum villosum* 
Ribes petraeum* 
Saxifraga umbrosa 
southern limit, viz. 
Saxifraga bircultis* 
Gentiana verna* 
Bartsia alpina* 
Rhinanthus major 
Trientalis Europaea 
Tofieldia palustris* 
It is interesting to observe that of these the greater proportion, 
marked by the asterisk, occur only in the most northerly and moun- 
tainous districts of the County. 
