Bakeu, F.R.S. : Geography of British Plants. 147 



that have most attracted my attention in this connection are these : 

 the first, that in Yorkshire some of the types which though plentiful 

 are sharply limited as regards individuality, in the neighbourhood of 

 London, though not more plentiful, slide off into others through 

 gradual intermediate stages. I have found that this holds good for 

 R, discolor, leucostachys^ and diversifolius. The other fact is, that in 

 the interior of the Lake country, round the shores of Windermere, 

 Derwentwater, Ulles water, and Coniston, the common types of the 

 surrounding country, especially codsius, corylijolius, and discolor, do not 

 penetrate. 



Turning next to the influence of soil, I found that in the North 

 Riding 40 species out of 872 natives, or one species out of every 22, 

 were manifestly influenced in their distribution by a predilection for 

 limestone rock, and that in the same area 40 species were restricted to 

 the neighbourhood of the sea. In this last case, no doubt chemical 

 reasons are the determinant element, but there are two points about 

 the matter worthy of further inquiry. Many of these characteristically 

 maritime species grow inland occasionally, like Armeria maritima 

 amongst the Wensleydale lead mines, and Flantago maritima on the 

 Teesdale sugar limestone. In some cases, as Cochlearia officinalis, we 

 have two well-marked varieties — one on the shore, and the other 

 amongst the mountains ; and we find that many of these types, 

 characteristically maritime when wild, grow easily without any special 

 treatment in inland gardens. As instances I may cite cabbage, 

 seakale, and celery. We want some one who is both chemist and 

 botanist to investigate the circumstances under which these maritime 

 plants grow away from the sea, and explain to us what it implies. 



As regards the minute circumstances connected with soil that affect 

 species-distribution, gardeners could teach botanists a great deal, if they 

 would keep their eyes open, in the routine of their daily work. The 

 most valuable recent contribution to our knowledge in this direction is 

 Kerner's " Cultur der Alpenpflanzen " published at Innsbruck in 

 1864, of which an excellent abstract in English appeared in the 

 number of Mr. Robinson's periodical called " The Garden," for Dec. 

 10th, 1881. Kerner's observations refer to the plants of the Alps of 

 Central Europe, and in the first place he classifies the species into 

 three groups, according to the amount of humus, or vegetable matter, 

 which they need. In the first group, those that can grow in a soil, 

 poor in humus, he places the alpine Crucifers, Crassulacese, Alsines, 

 Silenes, and most of the Compositae. In the second group, composed 

 of species that grow well on soil composed of vegetable humus and 



