W. L. Tower 
313 
In several species of insects I have found that progressive variation in a season is important, 
and any data for the determination of modes is of little use, unless, in gathering it, the fact be 
kept in mind that the individuals of a season differ from one another progressively throughout 
the generation. Thus, material taken at approximately one time gave me data which seemed 
to indicate a rai>id change from year to year, and this seemed the proper conclusion to 
draw from my data, until I discovered that my successive yearly lots of material were not at 
all capable of comparison, for the reason that momentai'y states only were represented and 
not the conditions for the different years. 
Statistical Biology seeks to determine the exact status of species as regards variation, 
expressed in modes, abmodalities and abnor'malities ; the direction, rate, and causes of variation 
in species; the suppression of old modes, the rise of new ones, and the shifting of modes; 
and the inheritance and permanency of these characters and changes. With such data, 
accurately determined for a number of species for a period of years, it will be possible to test 
the validity and broad application of some of the fundamental theories upon which modern 
Biology is built. In the gathering of these data, however, the most scrupulous care must be 
exercised to avoid error from undue selections, and to have the data cover as near as can be for 
each modal determination, one entire generation. 
Seriation of counts of the rays of C. leucantJieiiiuni from Yellow Springs, 
Greene Co., 0. 
Classes 
Lot No. 1, 
July 5, 1901 
Lot No. 2, 
July 30, 1901 
Totals 
12 
1 
1 
13 
8 
8 
U 
3 
3 
15 
6 
6 
16 
1 
8 
9 
17 
9 
9 
18 
8 
8 
19 
2 
12 
14 
20 
8 
19 
27 
21 
17 
26 
43 
22 
23 
11 
34 
28 
22 
10 
32 
24 
21 
10 
31 
25 
22 
8 
30 
26 
19 
5 
24 
27 
16 
4 
20 
28 
14 
6 
20 
29 
12 
4 
16 
30 
10 
2 
12 
31 
16 
4 
20 
32 
IH 
2 
20 
33 
29 
1 
30 
34 
20 
1 
21 
35 
6 
6 
36 
6 
6 
37 
0 
0 
38 
39 
2 
2 
Totals 
284 
168 
452 
liiometiilia i 
32 
