iTAr. V] 



THE SOIL 



93 



;cdge-shaped at the base and by liaviiig more delicate, more herbaceous, dull, 

 cciduous leaves. 



Both forms must be considered as fully adapted to their subtratum, for tliey 

 ourish on it witii the greatest vigour and abundance. Asplenium adultcrinum 

 Iinost entirely suppresses the common A. Trichomanes on serpentine, whilst the 

 riginal form A. viride has been only exceptionally observed. The typical A. 



diantum-nigrum sccnis completely absent 



om serpentine. Kalmus, speaking of the 

 ;ation of A. adulterinum and A. Trichomanes 

 car Einsiedel, says that tlie latter appears to 

 im to be quite a little people which is only 

 llowed on sufferance by its superior neigh- 

 ours and relatives ; and Milde makes the 

 illowing remarks about the same plant : 

 The first thing that struck me was the great 

 ensity of its growth, partlj' due to the large 

 umber of plants, partly to the immense clumps 

 •hich the plant often formed. I have never 

 bserved such vigorous growth in A. viride and 

 nly very rarely in A. Trichomanes '.' 



6. CALAMINE. 



The action on plants oflarge quantities 

 f the slightly soluble zinc ore usually 

 iiown as calamine (zinc carbonate and 

 licate) resembles that of serpentine in 

 ) far as it also induces hereditary modi- 

 cation in some plants, in this case Viola 

 itea and Thlaspi alpestre, the physio- 

 igical and oecological connexion of which 

 ith the nature of their substratum has 

 ^ yet obtained no interpretation. The 

 lants thus modified grow on a zinc soil 

 I great numbers and lu.xuriance, and do 

 Dt overstep its limits. 



Fig. 53. Viola calaminaria. 

 natural size. 



Half 



The calamine violet, Viola calaminaria, Lej. 

 '. lutea, van multicaulis, Koch.) (Fig. 53), 



tfers from other forms of Viola lutea by its rich ramification, its longer stem, 

 id its smaller corolla, which however varies somewhat in size. In the case 

 Thlaspi calaminare, Lej. et Court, the petals are broader than those of the type 

 rm, and are much longer than the sepals, while the filaments are shorter than the 

 pals. The zinc in the soil has induced in the one form an increase, and in 

 e other form a decrease in the size of the corolla. 



• Sadebeck, 1, 11. 



