SIZE, SHAPE AND PHYSICAL CONSTITUTION OF THE EGG. 115 
same environmental conditions since hatching and they began to 
lay at very nearly the same time. Further there are only 
slight differences in the degree and direction of variations in 
the monthly means of the same weight character for the sev- 
eral birds. 
The material has been brought together by calculating di- 
rectly for each weight character the monthly mean of all the 
eggs laid by the twelve birds. 
The means are given in Table 2. 
TABLE 2. 
Showing for Bach Month the Number of Birds Laying, the 
Number of Bggs Laid and the Mean Egg Weight, Yolk 
Weight, Albumen Weight and Shell Weight for the Twelve 
Birds which Completed their Second Year. 
Month. 
No. birds 
laying. 
No. eggs 
laid. 
Mean 
egg 
weight, 
gms. 
Mean 
yolk 
weight, 
gms. 
Mean 
albumen 
weight, 
gms. 
Mean 
shell 
weight, 
gms. 
Mean tem- 
perature 
in degrees, 
F. 
1910 
October 
1 
3 
48.56 
13.66 
28.13 
6.17 
48.40 
November 
12 
137 
47.48 
12.87 
29.11 
5.46 
34.95 
December 
11 
206 
48.99 
13.39 
30.38 
5.22 
19.55 
1911 
January 
12 
110 
50.37 
14.24 
30.88 
4.84 
18.15 
February 
10 
100 
53.53 
16.27 
30.94 
5.37 
14.56 
March 
12 
224 
54.25 
16.18 
32.46 
5.63 
25.20 
April 
12 
210 
54.42 
16.43 
32.48 
5.54 
40.90 
May 
12 
192 
53.73 
16.23 
32.12 
5.39 
59.25 
June 
12 
144 
53.66 
16.25 
32.23 
5.13 
62.30 
July 
11 
158 
52.22 
16.31 
30.83 
4.87 
71.20 
August 
11 
170 
54.75 
16.72 
32.53 
5.46 
66.20 
September 
11 
132 
55.44 
16.88 
33.13 
5.41 
57.20 
October 
9 
86 
56.68 
17.61 
33.23 
5.55 
46.10 
November 
4 
15 
58.51 
17.41 
35.57 
5.43 
34.40 
December 
4 
43 
59.20 
17.50 
35.93 
5.77 
28.00 
1912 
January 
5 
29 
61.30 
17.90 
37.72 
5.67 
10.90 
February 
8 
39 
54.73 
17.85 
31.88 
5.08 
17.70 
March 
11 
179 
59.03 
18.46 
34.71 
5.68 
27.00 
April 
12 
130 
56.12 
17.47 
33.10 
5.08 
43.50 
May 
12 
138 
55.63 
17.71 
33.47 
5.31 
57.10 
June 
11 
148 
58.10 
18.45 
34.30 
5.62 
63.80 
July 
12 
137 
56.97 
18.31 
33.46 
5.32 
67.20 
August 
10 
88 
57.16 
18.16 
33.61 
5.39 
62.50 
September 
11 
123 
58.46 
18.19 
34.69 
5.53 
57.50 
October 
9 
83 
61.64 
18.19 
37.20 
6.23 
49.80 
