Elementary Species in Nature 39 



varieties, the attributes of the latter with the 

 peculiarities of the former species. 



Besides the lutea, there are some other spe- 

 cies, nearly allied to tricolor, as for instance, 

 cornuta, calcarata, and altaica, which are com- 

 bined with it under the head of Melanium as a 

 subgenus, and which together constitute a syste- 

 matic unity of undoubted value, but ranging be- 

 tween the common conceptions of genus and 

 species. These forms are so nearly allied to 

 the heartsease that they have of late been made 

 use of in crosses, in order to widen the range 

 of variability of garden-pansies. 



Viola tricolor is a common European weed. 

 It is widely dispersed and very abundant, grow- 

 ing in many localities in large numbers. It is 

 an annual and ripens its seeds freely, and if op- 

 portunity is afforded, it multiplies rapidly. 



Viola tricolor has three subspecies, which 

 are elevated to the rank of species by some 

 authors, and which may here be called, for 

 brevity's sake, by their binary names. One is 

 the typical V. tricolor, with broad flowers, vari- 

 ously colored and veined with yellow, purple 

 and white. It occurs in waste places on sandy 

 soil. The second is called V. arvensis or the 

 field pansy ; it has small inconspicuous flowers, 

 with pale yellowish petals which are shorter 

 than the sepals. It pollinates itself without the 



