298 Formation and Flora of a Shingle Island. [Sess. 



tiny accumulations of sand and grit with a few fragments of 

 moss and scale-moss, which had collected in the crevices 

 underneath flat stones, &c. A lot of dihris — leaves and 

 grass stems, &c. — gets wound round the heads of such plants as 

 hard-heads, plantains, and rushes ; but the bushes on the island 

 collect by far the largest part. They already have curious 

 mounds of grass growing up high round their roots ; and the 

 fresh pieces of turf brought down by the river lodge there, 

 and have every chance of growing. Large collections of twigs 

 also lodge in the bushes ; aud much small debris is entwined 

 round their leaves. These bushes also play another important 

 part, as they protect the shingle from being washed away. 

 We noticed several instances where a regular ridge of shingle 

 extended westwards (i.e., down-stream) from a bush, the shingle 

 on both sides having been carried away by the stream. It 

 appears, then, that as soon as any bushes have established 

 themselves on a shingle bank, it has a much better chance of 

 becoming permanent, and its prospects of getting covered with 

 vegetation are perhaps improved. 



Chief aim of otcr investigation. — Our chief aim, in all these 

 investigations, was to record the entire flora of the Shingle 

 Island, and to ascertain as far as possible the sources from 

 which it was drawn. It became clear, at the outset, that 

 besides the island itself we should have to take into account 

 its immediate surroundings, namely, the adjoining fields, and 

 the narrow strip of land between them and the river, which, 

 for the sake of clearness, I shall call the riparian strip. We 

 thus found ourselves with three distinct tracts to study, each 

 with a character of its own and cettain plants peculiar to 

 itself. After indicating the general characteristics of all three 

 tracts, we shall give the complete list of the island's flora, and 

 note how it differs from that of the fields and the riparian 

 strip.^ 



Fields adjoining the Shingle Island. — The fields immediately 

 alongside the island have been cultivated for at least a hun- 

 dred years. Judging from the surroundings, they were origin- 



^ We have followed the nomenclature of the ' London Catalogue of British 

 Plants,' 9th edition, 1895, wherever possible ; but in some cases — e.g., Valeriana 

 officinalis — we have used the older aggregate name, because we did not dis- 

 criminate further when identifying our specimens. 



