38 REPORT OF THE COMMISSIONER OF FISHERIES. 
(4) The death rate among terrapin after the first season is so small 
as to be nearly negligible. It is found to be about 1 per cent in the 
second year, diminishing with age to one-half per cent and less. The 
principal mortality occurs in the first season, and is then found to be 
chiefly among the “runts,’’ which should probably be culled out in 
ordinary practice. While the death rate has been as high as 20 to 25 
per cent during the first season, it has now been reduced, partly 
through improved methods of sanitation, to less than 10 per cent. 
The losses are remarkably low when it is considered that deaths occur 
ponepaly when terrapin are very young and before they have 
ecome a source of expense, and that the productivity of the terrapin 
is such that even a loss of 30 per cent at this stage couid readily be 
compensated for by increasing the numbers hatched and saved for 
rearing. So far as regards disease and death rate the rearing of 
terrapin is a matter of much less difficulty than the raising of poultry. 
(5) The history of our experiments durmg many years gives 
strong grounds for belief that domestication of terrapin is accom- 
panied by increasing productivity and diminishing disease and 
mortality. Our experience indicates the advisability of retaining a 
select brood stock for a rather indefinite period, mstead of adopting 
new breeders from year to year, as might be done in stock raising. 
Some of the breeders have been in captivity for about 14 years. 
It may be noted that the experiments in terrapin culture have 
not the nature of small laboratory tests but are carried out upon 
such a scale as to be comparable to commercial operations. It is 
persis also to check our results against those obtaimable in a large 
ocal commercial venture which has adopted methods based upon 
those followed in the Bureau’s work. From this it appears that the 
various results gained in the Bureau’s experimental work are not to 
be taken as exceptional, but that they are, in a general way, typi- 
cal of what may be expected in cultural operations conducted accord- 
ing to sound principles and with the exercise of proper care. 
Fithare are now about 3,000 terrapins under observation and elas- 
sified in more than 25 experiments which are being directed to obtain 
definite answers to practical questions that yet demand attention 
and justify the continuance of the investigations. Among these 
are: What is the proper proportion to maintain between males and 
females, and what are the best conditions for prolificness in eggs and 
for successful hatching? What are the possibilities of improving 
rate of growth by selection, and what are the opportunities for pro- 
moting economy through proper culling or other methods? These 
are only some of the practical questions which warrant further inves- 
tigations. 
SURVEYS OF FISHING GROUNDS. 
Some further work has been done in extending the known limits of 
the blackfish grounds off the coast of North Carolina. The Bureau 
maintains a buoy on the principal grounds, which is of service to 
fishermen both in locating this particular ground and as a bearing 
from which to find other grounds. The fishery is not developed in 
proportion to the evident possibilities, owing partly to the lack of 
suitable boats and partly to the unwillingness of local fishermen to 
engage in operations at any distance from the shore. One or two 
crews have, however, taken advantage of the opportunities and the 
