122 THE AMERICAN NATURALIST. [Vor. XXXVI. 
TABLE D.— CONSTANTS OF ASTER PRENANTHOIDES Munur. 

BRAcTs. | Rays. | Disk FLorRETS. 
a ace nee aaan E NESE S EEE MS A EANA PASESER SS UM DN 
| 
| 
No. : | 658 658 658 
Mean 44.044072 28.037993 50.297872 
| ( 40-41 ^ ( 48-49. 
Mode 1 44-45 26-27 1 
| | 48-49 | L 52-53 
A.D, | 4-497002 31313229 4.884951 
Sio 5.716510 4.070071 6.310315 
PRAD + 3-855786 + 2.745263 + 4.256308 
PLE, M. | zx .150314 + .10702I + .165889 
REg. + .106288 + .075675 £ 417301 
CV. | 12.979068 14.516272 12.545890 


Result of the Successive Collections. — The remaining figures 
represent the conditions found in four successive pickings 
made from a single group of individuals of Aster prenanthoides 
Muhl 
I. Bracts. Figs. 21, 22, 23, and 24 show the frequency 
polygons of the bracts in the successive collections. In the 
first collection (Fig. 21) there was a single mode on 49-50, 
with the mean on 47.410256 and a strong positive skewness. 
In the second collection (Fig. 22) the curve broke up into 
three modes on 40-41, 44-45, and 48-51, while the mean fell 
to 44:342657. In the third collection (Fig. 23) the material 
exhibited two modes on 44-45 and 50-51, which correspond 
closely with the upper two modes of the second picking, the 
mean having fallen to 43.834532. At the last collection the 
curve, given in Fig. 24, showed a strong mode on 41-42, 
while the upper mode, which at this time occurred on.49—50, 
had become much less prominent, and a small mode had 
appeared on 33-34. The mean had continued to fall, and in 
this last collection was only 41.92045. ic : 
. . The table on page 124 will facilitate a comparison of the 
bracts from the four collections. e Ne 



