<i|f0l0gial gisttibuti0n of ^amt of tk 

 §d'5toI IHossfS. 



BY "W. W. STODDART, F.G.S, 



Received Decemher 5th, 1874. 



"VTATURAL selection is strikingly manifested in the localities 

 -*- ' chosen by plants of all classes and orders. Some prefer 

 Limestone, while others select the sandy soil of the Triassic or 

 Devonian formations. Some inhabit the driest.spots, while an equal 

 number are never found except in wet and marshy places. Indeed, 

 so well marked is this fact, that the nature of the ground is 

 betrayed to the Geologist by the plants with which he meets. 

 It would be idle to seek for the Salicorma, Glaux, or Salsola 

 except on the sea shore, or the brine springs of Cheshire and 

 Worcestershire. The Digitalis marks the presence of Sandstone, 

 while Sutehinsia and Arahis indicate Limestone. The botanist 

 knows that if he wishes to find specimens of Lraha, Saxifraga, or 

 Linaria cymldaria, he must search the tops of the neighbouring 

 walls, while the rubbish heaps must be visited for Tussilago^ 

 HyoscyamuSy and some species of Sisymlrium and Polygonum. 



