92 



BULLETIN OF THE BUREAU OF FISHERIES. 



The terrapin propagation study has been directed since its beginning by several 

 investigators. Originally Dr. R. E. Coker gave his attention to its possibilities and 

 prepared a report of his results for the North Carolina Geological and Economic Survey. 2 

 At the same time Prof. W. P. Hay began similar investigations in Chesapeake Bay. 

 In 1909 these were transferred to Beaufort, where Dr. Hay took charge of the experi- 

 mental work and continued giving it his direction from 1909 to 1915. During this 

 time H. D. Aller planned and carried out the feeding of yearling terrapins during the 

 winter in a warmed nursery house. Lewis Radcliffe relieved Mr. Aller in 1912 and was 

 later followed by S. F. Hildebrand. Some of the material herewith discussed is from 

 experiments begun by the two last-named investigators, but left unfinished because of 

 their removals from Beaufort. The present paper is based on the unorganized notes of 

 each of the above-mentioned investigators and also on the systematic observations 

 carried on under their supervision by Charles Hatsel, the terrapin culturist stationed at 

 Beaufort, N. C, since the experimental work was begun. The large share of credit for 

 the continuity and the accuracy of the observations of the entire experimental terrapin 

 propagation project is due Mr. Hatsel for his exceptionally careful, energetic, and 

 faithful work. The writer has had the direction of the experiments since the fall of 

 1919. B. J. Anson has assisted in organizing and tabulating the data discussed in 

 this paper and J. B. Southall has prepared the graphs. 



BROOD STOCKS OF THE EXPERIMENTAL FARM. 



The terrapins of the original brood stock, which are either the parents or grand- 

 parents of all the Carolina terrapins that are held in captivity and under observation 

 at the Beaufort station, were purchased in two lots, the so-called " original lot of North 

 Carolina breeders ' ' and the ' ' second lot of North Carolina breeders. ' ' To these was added 

 later, but kept separate, a number of adult Texas terrapins as brood stock. The pro- 

 duction in eggs and young throughout the years of captivity of these terrapins is herewith 

 tabulated (Table 1) and shown in graphic form (fig. 76). 



Table i.— Records of Breeding Stocks of Terrapins in Captivity at Beaufort, N. C. 



Stock and year. 



Original stock: 



1909 



1910 



191 1.. ..... . 



1912 



1913 



1914 



1915 



1916 



1917 



1918 



>9"9 



Males. 



Females. 



Eggs. 



Number. 



288+ 



598+ 



688 



732 



736 



923 

 921 

 722 



>757 

 '834 



Rate per 

 female. 



Young. 



Number. 



(?) 

 6.5+ 

 ■3- 9+ 

 16. o 



17.0 

 18.8 



23. 6 



23. 6 



 8. s 

 1 194 

 ' 21-3 



288 

 598 

 538 



610 

 594 

 836 

 813 

 639 

 "675 

 b 757 



Rate per 

 female. 



(?) 



6.5 



13- 9 



12.5 



14. 1 



15.2 



21.4 



20. 8 



16.3 



6 17-3 



l> 194 



Per cent 



eggs 

 hatched. 



" Five males taken from this lot for experimental purposes in 1911 were returned to it in 1919. 

 1 Estimated. 



(?) 

 (?) 

 (?) 



80. 

 90. 

 88. 

 88. 

 i>8 9 



'Coker, R. E. : The Cultivation of the Diamond Back Terrapin. 

 Raleigh, 1906. 



Bulletin No. 14, the North Carolina Geological Survey. 



