28 
BULLETIN OF THE BUREAU OF FISHERIES 
The Chesapeake terrapin is generally preferred on the market, but the differ- 
ence between it and the Carolina terrapin is so slight that large, fat animals of the 
last-mentioned variety are accepted readily as “Chesapeakes.” 
EXPERIMENTS CONDUCTED AND SOURCES OF INFORMATION 
At the present time (January 14, 1928) 33 lots of terrapins are on hand at the 
station. The animals composing the various lots, exclusive of those that comprise 
the original brood stock, were hatched and grown in captivity and therefore are of 
known age. Every lot itself forms the basis for a separate experiment or is a part 
of an experiment. The following are some of the experiments for which the various 
lots of terrapins are being used: (a) Space requirements for young and adults; (b) 
size of egg beds required; (c) natural sex ratio; (d) sex ratio required for breeding 
purposes; (e) practicability for increasing growth, hastening maturity, and reducing 
the death rate by feeding young terrapins during the winter; (f) the control of disease 
among recently hatched animals (young terrapins only are mentioned in this connec- 
tion, as no disease has occurred during the course of the experiments among animals 
a year or more of age); (g) several experiments in selective breeding; (h) two experi- 
ments in crossbreeding the Carolina with the Texas terrapin. Some of the experi- 
ments have not been carried on long enough or far enough to yield results, and these 
will not be reported upon at this time. Others have yielded noteworthy results, 
however, and the information derived forms the basis for the present report. 
The latest previous report 3 made upon this investigation is entitled “Further 
Notes on the Natural History and Artificial Propagation of the Diamond-Back 
Terrapin,” by R. L. Barney (Bulletin, U. S. Bureau of Fisheries, Vol. XXXVIII, 
1921-22 [1922], pp. 91 to 111). Although the present paper essentially is a progress 
report, nevertheless it is based upon the original data, all of which have been studied 
carefully. The data presented cover the entire period during which each experiment 
reported upon has been under way. In the interpretation of the data due considera- 
tion, however, was given to the published accounts. A different conclusion occa- 
sionally was arrived at, mainly on account of the much more extensive data now at 
hand and partly because of errors that were corrected and, no doubt, also in part 
because of a different personal viewpoint. 
PRODUCTION OF EGGS 
The production of eggs has varied from year to year within broods and even 
within lots of the same brood, as shown by tables presented herewith. Similar varia- 
tions have taken place among wild terrapins of unknown age confined for breeding 
purposes. For example, among a certain lot of wild breeders production has varied 
from about 7.6 to about 23.9 eggs 4 per female during the period 1915 to 1926, inclu- 
sive. It appears to be of interest to mention in this connection that wild terrapins 
have produced few eggs during the first two and three years of confinement. The 
3 U. S. Bureau of Fisheries Economic Circular No. 00, entitled “Diamond-Back Terrapin Culture at Beaufort, N. C.,’’ by- 
Samuel F. Hildebrand and Charles Hatsel, was issued in October, 192S. This short paper gives only the economic phases of the 
work and gives no specific account of the many experiments performed nor of the more scientific aspects of the work. 
A slightly larger number of eggs per female was produced than shown, as the terrapins themselves accidentally destroyed a 
few eggs from time to time and rats often destroyed an unknown number. Eggs thus destroyed are not taken into consideration 
in these data. 
