BIOLOGY AND NATURAL HISTORY 229 



indicating a gain of ii mm in 9 years. Probably North Carolina terrapin 

 do not often attain an undershell length much exceeding 5^ inches. It is a 

 well known fact that for many animals there is an inverse relation between 

 size and temperature during development. Animals of the same species may 

 attain larger sizes in more northern and colder waters. 



On the other hand, among individuals of any given brood, the variability 

 in growth is extreme. Coker (1906), Hildebrand and Hatsel (1926), Hilde- 

 brand (1929), and others, have remarked on the extraordinary variability 

 of turtles in respect to rate of growth. 



SUMMARY 



1. The diamond-back terrapin, once the most valuable (per unit) food 

 product of the coastal region, has depreciated greatly in value since the 

 time of World War I but there are indications of continued esteem and 

 perhaps of substantial recovery in market value. 



2. Presumably in consequence of exhaustive fishery the populations have 

 been seriously depleted in northern waters and in North Carolina. Produc- 

 tion in the State is now negligible. 



3. The waters of North Carolina in northern and southern parts are 

 within the respective ranges of terrapin of the "Chesapeake" and "Carolina" 

 types. 



4. Cultural experiments have been conducted at the U. S. Fisheries 

 Biological Station, Beaufort, N. C, since 1902, but chiefly from 1909 to 

 1948. Although over-all direction of the experiments has undergone many 

 changes, and several scientists have contributed substantially to this de- 

 velopment, great credit for continuity and success must be attributed to 

 the late Captain Charles Hatsel of Beaufort for most efficient care from the 

 beginning in 1902 until his retirement in 1947. 



5. Terrapin are readily kept in confinement for breeding and rearing at 

 relatively small expense for food. Data are available in various publications 

 regarding space requirements, sex ratios, diseases and mortality, and rate 

 of growth. Keeping newly hatched terrapin in warmed nursery houses and 

 feeding them during the first winter, not only reduces mortality during the 

 period of greatest helplessness, but also enables the terrapin to make two 

 years growth in one year. 



6. If a high market price can be depended upon, there is promise in 

 the breeding and rearing of diamond-back terrapin in privately managed 

 terrapin farms. 



7. In spite of much scientific study, particularly under conditions of 

 propagational experiments, there is still a paucity of information regarding 

 the natural history of terrapin in the wild. There is particular need of fuller 



