80 ADDISONIA 
variable a plant may be conceived of as having place in its genea- 
logical system at the growing end of its particular branch, impelled 
at that point of intensified unfoldment to far greater energy of 
variation than are more quiescent species that, stranded beside 
the main current of their family course, are left without the impulse 
to go forward into ready or tenacious deviations. 
Even more than this species other asters, notably the white wood 
aster (Aster divaricatus I.) and the New York aster (Aster Novi- 
Belgit I.) are prone to this truancy from the parental bounds, 
and the genus as a whole, with its multitude of related forms and 
its many subgeneric offshoots, may well be viewed as being itself 
terminal in position on some progressive branch of a strong family 
stem. 
The flowers of the blue wood aster by an occasional striking 
change appear with rays of purest white. 
EUGENE P. BICKNELL. 
EXPLANATION OF Pate. Fig. 1.—Flowering stem, Fig. 2.—lLeaf. Fig. 3, 
—Involucre, X 2, 
