340 
T. H. GOODSPEED AND R. E. CLAUSEN 
growing and flowering season is, with one possible exception to be 
noted in the following pages, the only representative distribution. 
Such a distribution expresses the entire demonstrable series of develop- 
mental changes in the flower. which accompanies the normal onto- 
genetic plant processes. It is hardly necessary to point out the bearing 
which results such as these have on the interpretation of the inheritance 
of similar characters based on a comparison of constants derived from 
small parental and Fi populations with very large F2 populations. 
The fact that is decidedly significant in connection with the study 
of the inheritance of flower size is that the distributions of means 
when different parts of the total population are measured at different 
times is so strikingly different from the truly representative distribu- 
tion derived from the measurement of all the plants throughout the 
whole season. 
In Tables II to V we are concerned with the flower size of three 
of the semi-sterile hybrids of TV. Tahacum varieties and N. sylvestris 
which have been mentioned in previous communications (cf. Good- 
speed, 1913, 2). Tables \\a and \lh have to do with the means 
Table I la 
Frequency Distributions for Spread of Corollas in Jj Fi Hm 
Designation 
Class Centers 
in Millimeters 
No. 
Mean 
Coef. Var. 
31 
32 
33 
34 
35 
36 
37 
38 
39 
I 
4 
4 
9 
35-33±-i5 
38.33±-ii 
36.67 ±44 
3i.67±.26 
i.89d=.30 
I.23it.20 
5.30^-84 
3-65±.58 
Means for first dates 
6 
3 
9 
I 
I 
I 
3 
I 
2 
9 
Means for last dates 
4 
2 
9 
Table l\h 
Frequency Distributions for Length of Corolla in 13 Fi Hm 
Designation 
Class Centers in 
Millimeters 
No. 
1 
Mean Coef. Var. 
51 
52 
S3 
54 
56 
57 
Means for totals 
I 
4 
4 
7 
9 
55-33=t.ii i.2id=.i9 
56.22rb.09 .74d=.i2 
55.oo±.i8; i.49±.24 
53.44i.281 2.36d=.37 
2 
9 
Means for mid dates 
3 
3 
9 
Means for last dates 
4 
3 
I 
9 
of spread and length of flowers on the plants of Fi Hm- The facts 
brought out in these tables emphasize those already demonstrated by 
