4 1 8 Relations between Geological Strata and 



united with the superstratum of mountain lime. It has been 

 stated in the Philosophical and Literary Society of Manches- 

 ter, by one of its most distinguished members (Mr. Moore), 

 that wherever the brushwood of the lime district in Derby- 

 shire is burnt down, the common Jrifolium pratense (Dutch 

 clover) springs up; and on the pastures round Stonehouse, 

 at Plymouth, I was informed by Lord Mount-Edgecumbe's 

 steward, a similar species is produced by throwing over the 

 land the crumbled soil of the harbour rock, which is com- 

 monly called Devonshire marble, a species of mountain or 

 primitive lime. 



Foxglove is common every where but on chalk ; and, how<- 

 ever usual the occurrence of this beautiful but noxious flower 

 is throughout England, the Isle of Wight scarcely boasts a 

 single specimen. 



The chalk districts afford the most striking illustrations. 

 Wherever you come to chalk, even at a depth below the soil, 

 there you find in abundance saintfoin, conglomerate bellflower, 

 nodding thistle, mountain galium, and dropwort meadow- 

 sweet, with a scarcity, almost a want, of the grasses, except 

 those allied to the agrostis or bent, a dry, hard, and slender 

 herbage. Here, too, the spider, bee, and fly orchises are 

 quite common. 



In the Isle of Wight, on the high downs near an open sea, 

 or on the level inland plains of Wiltshire, or on the slopes of 

 Brighton, Bognor, or Kent, in every variety of position and 

 climate, the same plants maintain their position on chalk, and 

 scarcely ever occur elsewhere. 



Objections to this theory must be numerous. For the sake 

 of brevity, let me simply state the most cogent, and attempt 

 an answer, on the principles here laid down. 



1. The number and variety of rocks are not in proportion to 

 the number and variety of vegetables. 



This incongruity may arise from the great fertility of plants. 

 Thistles, for example, may produce a hundred thousand 

 seeds, and the ferns many hundreds of thousands. Nature, 

 by this overproduction, may have provided for the waste oc- 

 casioned by loss of appropriate situation ; and experience in- 

 forms us, that millions of seeds do thus perish, or are laid in 

 a dormant state among strata of sand, clay, or loam, whence 

 they can derive no support : while simple induction would 

 convince us that, of the many millions of seeds which never 

 vegetate, not one half can be lost from any other cause, 

 as weather, imperfect structure, or want of room to grow. 

 They are possessed of means and powers to transport them? 



