DIAMOND-BACK TERRAPIN CULTURE 
49 
as well or slightly better, but the greatest gain made by a large lot occurred in the 
1916 brood, when 1,040 animals reached an average length of 39.2 millimeters on 
Figure 5.— Rate of growth of a selected lot of the brood of 1914 
May 25, 1917, when they were removed from winter quarters. The least growth 
attained to date occurred in the broods of 1911 and 1923, the animals in each brood, 
upon removal from winter quarters, being 
found to have reached a length of only 
30.9 millimeters. 
The average rate of growth of the 
1923 brood, as in several other broods, 
quite probably was considerably reduced 
because of experimentation with different 
kinds of foods and various kinds of treat- 
ment. For example, some of the animals 
of the brood of 1923 were fed salted fish, 
which proved to be less acceptable to the 
terrapins than fresh fish or oysters and 
produced slower growth. Then, too, some 
of the animals, for the purpose of experi- 
mentation, were greatly crowded in the 
tanks in which they were held, and that 
appears to have retarded growth. The different kinds of foods used and their 
relative value, as well as the different conditions with respect to crowding, heat, 
water supplied, etc., are discussed elsewhere in this section. It appears to be suffi- 
cient to state at this point that a considerable number of experiments were run and 
that several of them actually retarded growth, which, however, was not unexpected. 
19/S m 1917 1918 /S/9 /920 /9ZI 
Figure 6. — Rate of growth of a large lot of the brood of 
1915. This lot was discarded in the spring of 1921 
