BY DR. M. B. BORKHAUSJEN. 210, 



separate these three plants into so many species, 

 which, however, appear to be mere varieties. The 

 distinguishing characters attributed to each of them 

 are not so constant or exclusively their own, as to 

 entitle them to the rank of real species. Accor- 

 ding to the difference of soil the plant varies very 

 much ; with stalk upright or trailing, simple or 

 branched below; with root-leaves alternate or 

 opposite, obovate or oval, cauline leaves lanceolate 

 or linear. The soil most favourable to its growth, 

 and in which it attains the most intense bitterness, 

 appears to be a fine argillaceous soil, covered with 

 bog-earth, such as is found on the Bergstrass- 

 mountains. Here the plant always appears as 

 Polygala amara, varying, however, frequently, 

 both with respect to the stem, which is either 

 simple or branched below, and to the root-leaves 

 which are generally opposite, but also alternate, 

 even on the same specimen. As the argillaceous 

 soil is gradually mixed with gravel, and at last 

 becomes entirely gravelly, ' the plant loses more 

 and more of its luxuriant appearance, both the 

 radical and cauline leaves become narrower, 



