RECOGNITION OF THE CHARACTER OF SOILS. 521 



It is very interesting to note in these analyses the inverse ratio in the 

 absorption of potash and lime by the maritime pine, which seems to be 

 unable to defend itself against excessive absorption of lime and thus 

 experiences a dearth of potash which naturally interferes with the for- 

 mation of starch and chlorophyl ; hence probably induces the chlorosis 

 so well known to occur on excessively calcareous soils. The lime-loving 

 Corsican pine takes up a larger total amount of ash and more phos- 

 phoric acid, and nearly three times as much potash, but considerably 

 less lime than did the maritime pine on the same calcareous soil. 



The corresponding analyses made by Fliche and Grandeau, of the 

 leaves and wood of chestnut grown on the same two kinds of soils, gave 

 in general the same results ; and they add that the smaller content of 

 iron absorbed by the calcifuge trees when grown on calcareous soil point 

 also to a deleterious influence upon the normal formation of chlorophyl. 



Following Fliche and Grandeau, Bonnier 1 made corro- 

 borative tests by sowing seeds of the same plants, both cal- 

 ciphile and calcifuge, upon the two kinds of soils, and noting 

 the differences in their mode of growth and internal structure. 



Calciphilc, Calcifuge and Silicophilc plants. 



The subject has been somewhat exhaustively discussed by 

 Contejean 2 who enumerates and has classified under the three 

 general heads of calciphile, calcifuge and indifferent, over 

 1700 species of European plants. Unfortunately he had but 

 few soil analyses at his disposal, and was inclined to consider 

 as non-calcareous, most soils that gave no effervescence with 

 acids. But notwithstanding this disadvantage so far as his 

 contention of the efficacy of chemical soil-composition, and 

 especially of lime is concerned, he disproves very effectually 

 the physical theory of Thurmann, by numerous examples from 

 France and elsewhere in Europe; and also disposes very defi- 

 nitely of the claim that there is a special class of " silicophile " 

 plants. He concludes that silica (and sand) is merely a neu- 

 tral and inert medium which offers refuge to the plants " ex- 

 pelled " by lime; and that clay similarly exerts no chemical but 



1 Bull, de la Societe Botanique de France, tome 26, 1879. 



2 Geographic botanique. lufluence du terrain sur la vegetation. Baillere et 

 et Fils, Paris, 1881, 143 pp. 



