DIAMOND-BACK TERRAPIN CULTURE 
35 
Table §. — Production and fertility of eggs of the original icild brood stock, most of which were confined 
between 1909 and 1912. Males, 39; females, 72 1 
Year 
Eggs 
laid 
Young 
hatched 
Per 
cent 
fertile 
Year 
Eggs 
laid 
Young 
hatched 
Per 
cent 
fertile 
Year 
Eggs 
laid 
Young 
hatched 
Per 
cent 
fertile 
1912 
1, 337 
1, 374 
1,411 
1,480 
1,415 
1, 275 
1, 121 
1, 289 
1, 381 
1,415 
1, 335 
1,215 
83.9 
93.9 
97.9 
95.7 
94.4 
95.3 
1918 
1,157 
1,451 
939 
531 
615 
686 
1, 113 
1, 398 
915 
512 
566 
654 
96.2 
96.4 
97.5 
96.5 
92. 1 
95.4 
1924 
870 
719 
1, 065 
733 
829 
680 
985 
626 
95.3 
94.6 
92.5 
92.2 
1913 
1919 
1925 
1914 
1920 
1926 
1915 
1921 
1927 •___ 
1916 
1922 
Total..- 
17, 058 
16, 084 
94.2 
1917 
1923._ 
1 The number of females in this brood stock was reduced from 123 in 1912 to 72 in 1927, which accounts in part for the smaller 
number of eggs produced during recent years. 
Table 9. — Production and fertility of eggs of the 1909 brood, which hibernated. Males, 2; females, 4 
Year 
Eggs 
laid 
Young 
hatched 
Per 
cent 
fertile 
Year 
Eggs 
laid 
Young 
hatched 
Per 
cent 
feiiile 
Year 
Eggs 
laid 
Young 
hatched 
Per 
cent 
fertile 
1915 
96 
17 
17. 5 
1920 
140 
126 
90.0 
1925 1 
119 
116 
97.5 
118 
75 
fi3 5 
1Q21 
129 
120 
9.3 1 
1917 
98 
72 
73 ! 5 
1922 
118 
114 
96. 6 
Total 
1,293 
1,098 
85.0 
1918 
117 
112 
95.8 
1923 
132 
129 
97.7 
1919 
137 
129 
94.2 
1924 
89 
88 
98.9 
1 Discontinued after 1925. 
Table 10. — Production and fertility of eggs of the 1910 brood 
Year 
Fed first and in part 
in the second winter. 
Males, 13; females, 
116 
Hibernating each 
winter. Males, 5; 
females, 87 
Year 
Fed first and in part 
in the second winter. 
Males, 13; females, 
116 
Hibernating each 
winter. Males, 5; 
females, 87 
Eggs 
laid 
Young 
hatched 
Per 
cent 
fertile 
Eggs 
laid 
Young 
hatched 
Per 
cent 
fertile 
Eggs 
laid 
Young 
hatched 
Per 
cent 
fertile 
Eggs 
laid 
Y oung 
hatched 
Per 
cent 
fertile 
1915 
39 
34 
87.2 
1923 
710 
648 
91.3 
360 
233 
64. 7 
1916_ 
754 
587 
77.9 
38 
37 
97.3 
1924. 
697 
606 
87.0 
304 
218 
71. 8 
1917. 
1,071 
902 
84.3 
260 
214 
82.3 
1925_ 
592 
549 
92.8 
283 
223 
78.8 
1918 
1,015 
934 
92.2 
379 
348 
91.9 
1926 
757 
652 
86.2 
281 
203 
72. 3 
1919 
1,428 
1, 136 
79.5 
633 
475 
75. 1 
1927. 
1, 071 
768 
71.7 
318 
221 
69.5 
1920. - 
1 , in 
932 
83.9 
456 
263 
57.7 
1921 
768 
687 
89.5 
187 
128 
68.5 
Total 
10, 950 
9, 228 
84.2 
3, 961 
2,836 
71.6 
1922 
937 
793 
84.7 
462 
273 
59.1 
Table 11 .-—-Production and fertility of eggs of the 1911 brood 
Year 
Fed first 3 winters. Males, 
10 “old”; females, 78 > 
Hibernated each 
Males, 3; females, 35 
yinter (2 lots) 
Males, 3 “old”; females, 38 * 
Eggs laid 
Young 
hatched 
Per cent 
fertile 
Eggs laid 
Young 
hatched 
Per cent 
fertile 
Eggs laid 
Young 
hatched 
Per cent 
fertile 
1917 3 __ 
445 
417 
93. 3 
1918--. 
628 
582 
92.7 
1919 
973 
821 
84.4 
1920 - 
641 
572 
89.3 
4 250 
59 
23.6 
187 
152 
89. 1 
1921 
336 
302 
89.9 
394 
182 
46.2 
160 
114 
71. 4 
1922- - 
515 
461 
89.6 
387 
228 
59.0 
170 
127 
74.2 
1923 
561 
529 
94.3 
452 
305 
67. 5 
224 
174 
77.7 
1924 
529 
471 
89. 1 
353 
252 
71.4 
253 
215 
85.2 
1925. 
335 
311 
92.9 
367 
329 
89.7 
181 
169 
93.4 
1926 
673 
532 
79. 1 
336 
290 
86.3 
294 
245 
89.4 
1927 
613 
463 
75.5 
454 
288 
61.2 
393 
320 
81.4 
Total 
6,249 
5, 461 
87.3 
2,993 
1, 933 
64.5 
1,862 
1, 516 
81.4 
1 This lot of terrapins upon maturity proved to be all females. 10 old males taken from the original brood stock of wild 
terrapins of unknown age were then added. 
2 Three old males taken from the original brood stock were added in 1919. 
3 In 1915 and 1916 a few eggs were produced but they are not considered in calculating fertility, as the number is too small to 
be of significance. 
4 Eggs were produced for 2 years prior to this date but are not considered in calculating fertility as the females were penned 
without males. 
