32 
BULLETIN OF THE BUREAU OF FISHERIES 
Table 5. — Average number of eggs 'produced per female of the brood of 1912 
Runts 
Selects 
Runts 
Selects 
Year 
Entire 
lot 
All 5H 
inches 
and over 
in length 1 
Entire 
lot 
All 5J4 
inches 
and over 
in length 1 
Year 
Entire 
lot 
All hVi 
inches 
and over 
in length 1 
Entire 
lot 
All 5 y 2 
inches 
and over 
in length > 
1919 
2.4 
5.0 
1.6 
2. 5 
1925 
5. 1 
9.0 
1.7 
8.9 
1920 
4. 5 
21. 1 
2. 5 
31. 5 
1926 
8. 1 
3. 7 
1921 
4. 1 
1.9 
1927 1 
8.5 
6.9 
6.4 
7.6 
19.5 
18.1 
3.2 
2. 1 
41.0 
14. 2 
1923 
Average 
5.8 
14.6 
3.0 
19. 6 
1924 ... 
6. 1 
3.6 
i Female terrapins less than inches long apparently do not lay eggs. Therefore the rate of production shown in this column 
is the actual rate per sexually mature female. Measurements of the size of the terrapins are not available for every year and, there- 
fore, the rate of egg production per mature female can not always be given. 
Table 6. — Average number of eggs produced per female of the brood of 1913 1 
Year 
Entire 
lot 
All hYi 
inches 
and over 
in length 2 
Year 
Entire 
lot 
All 5V 2 
inches 
and over 
in length 2 
1920 -- 
0.4 
1925__ 
0.8 
4. 1 
1921 
.4 
1926- 
1.5 
1992 __ 
1.8 
18. 2 
1927 
3.1 
1. 2 
8. 9 
1 924 
1.4 
Average. 
1.3 
10. 4 
■ These animals were fed the first winter. 
2 Female terrapins less than 5H inches long apparently do not lay eggs. Therefore, the rate of production shown in this column 
is the actual rate per sexually mature female. Measurements of the size of the terrapins are not available for every year and, there- 
fore, the rate of egg production per mature female can not always be given. 
Table 7. — -Average number of eggs produced per female of the brood of 1914 1 
Year 
Entire 
lot 
All 5^ 
inches 
and over 
in length 
Year 
Entire 
lot 
All 5J4 
inches 
and over 
in length 
0.4 
.3 
.8 
1.4 
1.6 
17. 5 
1925 
0. 7 
1. 7 
4. 5 
6.8 
1926- 
6.8 
12.1 
1927. 
1923 -- -- - 
Average... ... 
1.4 
10.8 
1 These animals were fed the first winter. 
FERTILITY OF EGGS 
The percentage of fertility of the eggs has fluctuated greatly from year to year 
and often within a single small lot. For example, in a lot of terrapins hatched in 
1910 (fed the first winter), which consists of 13 males and 116 females, the percentage 
of fertile eggs has varied from 79.2 to 92.8 the average for the period 1915 (when the 
terrapins laid for the first time) to 1926, inclusive, being 85.2 per cent. In another 
lot hatched in the same year (1910), but which was allowed to hibernate each winter, 
now (1928) consisting of 5 males and 87 females, fertility has ranged from 57 to 91.9 
per cent, with an average for the period 1917 6 to 1926, inclusive, of 71.8 per cent. 
« This lot laid for the first time in 1916, but the number of eggs produced was so small that the results for that year do not appear 
to be worthy of consideration. 
