io6 



BULLETIN OF THE BUREAU OK FISHERIES. 



many terrapins which suffer an attack of the disease in question and again recover 

 their well-being. The subject of mortality among the young terrapins is discussed 

 on page 108. 



It is of interest to note in further discussion of feeding two winters and its lack of 

 advantage to the culturist the fact that, from average measurement, the hibernated 

 terrapins reach the 5-inch mark approximately one year and one-half after those fed 

 two winters. Referring again to the 1910 brood, the lot fed one winter reached the 

 5-inch mark two years before the 1910 hibernating group. It may then, perhaps, be 

 that two winters' feeding may slow down growth rather than hurry development. It 

 will be noted, too, that egg production in the 1910 brood lot fed one winter is negligibly 

 different as regards the year of substantial egg production from that of the 191 1 lot fed 

 two winters 



1912 BROOD. 



The 1912 brood was fed the first winter and allowed to hibernate each winter there- 

 after. In the spring of 1914 there was made a selection of 100 each of the smallest and 



MM. 



150 



140 



130 



120 



110 



100 



90 



80 



70 



60 



50 



40 



30 



20 



10 



1912 1913 1914 1915 1916 1917 1918 1919 1920 



Fig. 8j. — Growth of 1912 broods of original Carolina and Texas brood stocks. E^g produc- 

 tion and hatch per female per year expressed, respectively, by figures on the curves. 

 , Offspring of Texas brood stock, fed one winter; , offspring of Caro- 

 lina brood stock, selected from winter-fed lot for large size October 1, r9ij; , 



offspring of Carolina brood stock, selected from winter-fed lot as runts October 1, rc>i.?. 



largest grown terrapins of the stock. These two lots were kept separately, and their 

 growth and egg production to 1920 have been observed. The lot selected for large 

 size after the first two years did not exhibit as unusual growth as it had in the first 

 winter, while the "runts" after 1915 showed relatively much faster growth. Their 

 average length in 191 7 was about 10 mm. greater than the lot which had been chosen 

 originally for its early rapid growth. Both lots produced eggs in the same year (19 19) 

 when they were 7 years old. It is of interest to note in this connection that the "runt" 

 group averaged 2.3 eggs per female, while the "selects" averaged 1.6 eggs per female. 

 It is suggested, then, from this brood stock that selection with a view toward 

 earh' attainment of salable size or early and increased egg production took place at too 



