829 



opus magnum, the ' His tor ia Plantarum, 1 does Ray intimate the 

 slightest suspicion of hops not being indigenous to this country, and 

 he was one by no means hasty in admitting dubious species to the 

 rights of natives. Whence, then, the disposition of some moderns to 

 regard the hop as a naturalized foreigner with us ? I hope on some 

 better pretext than the mere follow-my-leader principle, because Sir J. 

 E. Smith says in 'English Flora' (vol. iv. p. 241), " I have sometimes 

 suspected Hops not to be indigenous, which was also the opinion of 

 Lightfoot with regard to Scotland." We are not bound, nor do I 

 think we ought to attach importance to any man's mere suspicions, 

 unless he condescends to show cause for entertaining them. That 

 the hop may not be indigenous to Scotland I think highly probable, 

 for as I have before observed, many plants fall far short in the British 

 Isles of the latitude they attain on the continent, and the hop may be 

 one of these. The striking difference observable in the variety and 

 nature of the species composing the floras of Hants and Forfar, for 

 example,* is much greater than is due to mere diminution of the 

 mean annual or summer temperatures, or even to the higher latitude 

 of the Scottish county. The true cause of the rapid failure of so large 

 a number of south of England plants before reaching the Scottish pa- 

 rallels, is to be sought in the greater humidity and cloudiness of the 

 climate, and comparative deficiency of direct solar light, so essential 

 to the spontaneous growth of plants, although in general but little af- 

 fecting their health and luxuriance under cultivation. An atmosphere 

 often at the point of aqueous saturation, deposits a portion of its 

 moisture when in that condition upon trifling depressions of tempera- 

 ture, and the vapour, now rendered visible, by impairing the transpa- 

 rency of the air, intercepts, even in the absence of clouds, much of 

 the sun's light and heat, which in a clearer and drier sky would exert 

 its direct influence on vegetation. If the heat of our summer be not 

 very much above that of the same season in the north, it commences 

 earlier, and is protracted into an autumn of longer duration, dryness 

 and serenity, better able to ripen the vegetable tissues, and bring the 

 seeds of plants to maturity. It is from our proximity to the conti- 

 nent, and the greater breadth of the mainland of England along its 

 southern coast than elsewhere, that our atmosphere is less loaded with 

 clouds and vapour than is that over the narrow and deeply indented 

 promontory of North Britain, environed by a wide expanse of water 



* I select Forfarshire as being the Scottish county of which, through the labours 

 of Don and Gardiner, we possess the fullest published flora. 



