president's address. 173 



sian Limestone district to the nortli of Hartlepool, I thought it 

 probable that the soil of that field might be somewhat calcareous, 

 and so account for the appearance of a plant which usually 

 grows in chalky localities. I dug up several plants by the roots, 

 and brought with me some soil attached; this, on being sub- 

 mitted to the action of muriatic acid, I saw did not exhibit any 

 trace of lime : the soil, in fact, proved a strong, reddish clay, or 

 purely argillaceous. The other example was afforded in another 

 chalk-loving species — namely, Salvia Verbenaca, which is so com- 

 mon in the chalk of Cambridgeshire, but, in the county of Dur- 

 ham, I had only noticed it before, in a limestone field and quarry, 

 at Hartlepool. On June 25th last I gathered a plant in a dry, 

 high bank, near Thorp, the soil being gravelly. Some of this 

 soil and gravel I tested with muriatic acid, and observed, by a 

 distinct effervescence, that the latter possessed some proportion of 

 lime. 



Here, indeed, the Salvia Verbenaca, unlike the pyramidal Orchis, 

 was growing in a situation containing a portion of its favourite 

 calcareous matter. 



Again, connected with the increase and dispersion of species, 

 the sides and banks of the numerous railways throughout the 

 kingdom will afford many habitats for new plants, and for the 

 increasing of rarer species. This last summer, I myself was 

 fortunate in finding Astragalus hypoglottis^ remarkably luxuriant 

 in size, Anthyllis vidneraria, Senecio viscosus, Sinapis muralis, 

 Medicago sativa, and two or three more plants, on the sides of the 

 railway between Greatham and Norton. Some of these had, 

 most likely, been taken there with ballast from Hartlepool. 



When I tell you, from a Parliamentary return, made up to the 

 end of last June, that the length of railways, opened in the 

 United Kingdom, came to 8,506 miles, and allowing 12 acres to 

 a mile of railway on the average, you will see the enormous dis- 

 trict thus taken up by railways will amount to no less than 

 102,072 acres. Here, then, a goodly portion of those acres by 

 the railway-sides, being left wild and uncultivated, will allow 

 the natural sowing, growth, and increase of many rare plants. 



The following are some of the less common species, which I 



