Rothrock. — A Nascent Variety of Bmnella Vulgaris, /,. 65 



adaptation to the situation is most decided. The question 

 still may be considered an open one as to whether it has 

 developed as suddenly as it appears to have done. 



Brunella vulgaris varies greatly in England in height, shape 



of leaves, etc. It has long been known here in meadows and 

 open places, but nowhere, so far as my observation goes, has 

 this low-flowering variety been found in quantity save in 

 lawns which are frequently and closely "mowed off." 



The late Dr. Darlington, who was a close observer, speaks 

 of the plant as common in meadows, but expressly declares 

 that it is not pernicious. The low form, however, is distinctly 

 pernicious on the shaded lawns of eastern Pennsylvania. A 

 point to be decided is whether it could have spread so rapidly 

 as it has done but for the disadvantage under which the 

 shade has placed the grass. 



There is the further fact to be noticed that this variety, on 

 the whole, produces fewer flowers and consequently fewer 

 seeds than the typical form; and in like measure that its in- 

 crease by shoots rooting from the nodes is correspondingly 

 greater. The plants produced in this manner are so numerous 

 as to form dense mats. This is interesting, not only because 

 it illustrates forcibly the relation between diminished repro- 

 duction by seed and increased bud or shoot reproduction, but 

 because it in part explains the rapidity with which the variety 

 seems to have been developed. The chance of return to the 

 typical form has been reduced to a minimum by growth from 

 buds instead of from seed. 



