238 



baker's north YORKSHIRE. 



minima conspicuously higher ; but the sums of summer temper- 

 ature are appreciably lower in proportion to the annual means, 

 The following table gives the number of species of the 

 Flowering Plants and Ferns which have been noted at the various 

 elevations from the low country upwards : 



ALTITUDINAL RANGE OF THE FLOWERING PLANTS AND FERNS 



OF NORTH YORKSHIRE. 



Height in Yards. 



Number of 

 Species. 



Per centage of total flora. 



Coastlevel& below looyds. 



859 



86 



At 50 — 100 yards 



853 



85 



150 





725 



72 



200 





656 



66 



250 





589 



59 



300 





520 



52 



350 





415 



41 



400 





3S2 



38 



450 





303 



30 



500 





270 



27 



550 





213 



21 



600 





174 



17 



650 





126 



13 



700 





III 



II 



750 





90 



9 



800 





68 



7 



850 





24 



2.1 



It has been explained in the chapter on Climate that 86 of 

 these species are essentially characteristic of a climate more 

 boreal than that of our low country ; but that the Montane 

 species reached at any altitude as we ascend never compensate 

 in number for the Ascending species which cease. In considering 

 this table of the altitudinal range of species in connection with 

 climate we must also take care to bear in mind what has been 

 said respecting the stational range of plants, and to remember 

 that, as we gradually ascend, not only are the sums of summer 

 heat lowered, but that the range of station for plants also becomes 

 gradually restricted. For instancCj to recur to the adjectives 

 employed to denote the different kinds of station, we may say, 

 speaking in general terms, that when within our Umits an altitude 



