266 Non-Isohihlc Races. 



vegetable kingdom and occurs in all the larger groups 

 and especially in most families of flowering plants.^ 



At that time some of the most widely cultivated forms 

 were the ribbon grass, Phragmitcs anindinacca z'aricgata, 

 and the variegated holly. Ilex Aquifoliwn. Both are 

 still much grown in gardens, the ribbon grass being rela- 

 tively uniform, the holly highly variable. Of the latter 

 there is a variety with white-edged leaves, besides the 

 ordinary one with flecked leaves. Phraginites is differ- 

 ent in many respects from genuine variegated plants and 

 is much less variable in its character. The Ilex, however, 

 is highly variable and often bears green shoots which 

 may soon supersede the others on account of the greater 

 facility with which they can obtain nourishment. A fine 

 variegated bush of this species, or of any other, may be- 

 come entirely green, whenever the green branches are 

 not cut away every year. Thus it is probable that many 

 specimens of the holly, which are now quite green, were 

 originally variegated and were bought and planted as 

 such. On closer examination we often find on them an 

 occasional variegated twig which proves the correctness 

 of this supposition. This is also the case with the horse 

 chestnut, of wdiich many older trees still living were 

 planted at a time when the variegated variety was in 

 special favor. Since then their foliage has become green 

 and their original character is no longer seen. But an 

 occasional checkered branch, or even the numerous small 

 twigs with white leaves along the main stem, betrays the 

 original variegated condition of the specimen. In the 

 same way many cases of single variegated twigs on 

 green bushes and trees are not to be regarded as the indi- 



* ScHLECHTENDAHL, Luinaea, 1830, V, p. 494. Very little seems to 

 be known about variegated mosses and thallophytes. 



