50 
BULLETIN OF THE BUREAU OF FISHERIES 
If the sole aim had been to produce the greatest gain possible, a much better average 
rate of growth undoubtedly could have been produced. 
The excellent growth made by the winter-fed lot of the 1910 brood is noteworthy, 
especially because of the seemingly unfavorable conditions under which it was held. 
A special house, as already indicated, was not yet available. Therefore, the animals 
were placed in the pump house at the station. The tanks were so arranged with 
respect to the windows that they received the rays of the sun through the window 
glass during a part of the day. No special heating plant was provided. Some heat, 
however, was obtained from the steam boiler used for pumping water, but the boiler 
was used only intermittently and not every day. On especially cold days some 
Figure 7. — Rate of growth of two lots of selected terrapins of the brood of 1916. Line D represents 
offspring of domestic stock and line W that of wild stock 
extra heat was supplied from oil stoves that were run only on such occasions. It is 
quite remarkable, in the light of present knowledge, that such excellent results were 
obtained under these circumstances, and furthermore, as shown elsewhere, the death 
rate was extremely low. A part of the next brood (that of 1911) was kept under 
identical conditions, and although the death rate remained remarkably low, the rate 
of growth, as already indicated, was as low as it has been to date (1928) for any 
winter-fed lot. Somewhat similar fluctuations with respect to growth, as shown by 
Table 20, have taken place from year to year. They have occurred, also, within a 
brood among animals of the same parents and not infrequently among the small 
lots held in adjoining compartments of the same tank, receiving identical treatment. 
It is impossible, as yet, to explain the reason or reasons for all fluctuations. 
