1904] SHULL—PLACE-CONSTANTS FOR ASTER 337 
nis the whole number of variates, v,’ and v,’’ are the deviations of 
the assumed means from the true means, and o’ and o” the errors 
of mean square or “standard deviations” respectively of the subject 
and relative categories.3 
III. LOCALITY AND HABITAT. 
Flowers collected from the hillsides differ in a marked way from 
those of the same species collected in the lowlands of the same locality, 
ashas been shown in many instances by DE Vries, Lupwic, REINOHL, 
and others. This is a question of habitat. It remains an unsolved 
problem whether plants are not so sensitive to edaphic and local 
climatic conditions as to make impossible the derivation by statistical 
methods of anything more fundamental than the fact and the degree 
of this extreme sensitiveness. This problem can be solved only by 
long and carefully conducted investigations. In order that we may 
discriminate between the influences of habitat and locality in making 
Studies in variation, it becomes necessary to record as carefully as 
Possible the habitat in which the material has been collected, and so 
t0 indicate the locality that future investigators may visit the identical 
area studied, 
"The definite character both of habitat and of locality has strongly 
‘ommended the choice of this particular area of Aster prenanthoides 
for such thorough investigation as is needed to elucidate the complex 
Problems involved in work of this kind. | 
oe is a small village on the boundary between ns — 
Sunties, Ohio, in lat. 39° 48’ 43” north and long. 83° 48" 41 
st The Little Miami River, on whose northern bank the village 
eMeUpIES @ post-glacial channel in massive gray Niagara lime- 
saieig a deep and narrow gorge widely known for the wpe 
nety. About one kilometer west of the village two sma 
Say the river from the north. Both of these apsione? 
; ave Cut gorges in the limestone, but, being unable to ar : 
the level <a rapidly as does the river, they have been left one a ty 
hea the river In hanging valleys. At about 10-20™ trom 
Yellow Springs turnpike crosses these streams by two seers 
" “ne area chosen as the source of material for this study 1s 
3 i : 
i Tisme thod displaces DunckEr’s method in the second edition of DAVENPORT S 
Statisg methods which has just appeared. 
