THE TERRAPIN SCALE. 



Table III. — Rudimentary eggs and embryos from developing females of the terrapin 

 j, taken at Mont Alto, Pa., during the seasons of 1912 and 1913. 



Date of dissec- 

 tion. 



Females 



dissected 



on given 



dates. 



Large 

 embryos. 



Rudi- 

 mentary 

 eggs. 



Date of dissec- 

 tion. 



Females 



dissected 



on given 



dates. 



Large 

 embryos. 



Rudi- 

 mentary 

 eggs. 



1912. 



May 27 



May 28 



Do 



May 29 



Do 



May 30 



Do 



Do 



June 5 



Do 



June 6 



June 7 



1 

 1 

 2 

 1 

 2 

 1 

 2 

 3 

 1 

 2 

 1 

 1 



604 

 271 

 297 

 349 

 386 

 625 

 463 

 573 

 362 

 696 

 824 

 684 



Many. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 Few. 



Do. 



1912. 



June 15 



Do 



1913. 



May 16 



June 4 



June7 



Do 



Do 



Do 



Do 



Do 



1 



2 



1 



1 

 1 



2 

 3 



4 

 5 

 6 



747 

 611 



632 

 881 

 734 

 758 

 689 

 785 

 663 

 598 



Few. 

 Many. 



Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 



The data given in Table IV show the number of embryos pro- 

 duced by 13 normal scales during the season of 1912. These data 

 were obtained by isolating the individual scales with tree tangle- 

 foot and taking the daily emergence. When these scales loosened 

 at the end of their reproductive periods they were removed and 

 dissected. The average number of embryos per scale was 406.34. 

 In this experiment approximately 50 per cent of the embryos that 

 formed appeared 'as migrating larvse. 



Table IV. — Record of progeny and embryos from 13 parent terrapin scales, season of 



1912, at Mont Alto, Pa. 



No. 



Date of 

 dissec- 

 tion. 



Number 

 of em- 

 bryos, 

 emerging 

 as larvse. 



Embryos 

 taken by 

 dissec- 

 tion. 



Total 

 embryos. 



Condition of embryos 

 removed by dissec- 

 tion. 



Condition of scale 

 when taken for dis- 

 section. 



1 



1912. 

 July 12 

 15 

 3 

 15 

 15 

 10 

 15 

 12 



15 

 15 

 15 

 15 

 15 



142 

 189 

 214 

 245 

 189 

 137 

 119 

 303 



220 

 168 

 187 

 349 

 291 



451 

 60 

 204 

 218 

 192 

 37 

 150 

 326 



195 

 138 

 22 

 193 

 343 



593 

 249 

 418 

 463 

 381 

 174 

 269 

 629 



415 

 306 

 209 

 542 

 634 



One-third dead 





2 



Do. 



3 . 



do 



Do. 



4 



do 



Nearly exhausted. 



5 



do 



All dead 



6 



Do. 



7 



.. do.... 



Do 



8. . 



One-fourth dead 



Mostly dead 



Black; nearly ex- 

 hausted. 

 Nearly exhausted. 



9 



10 



All dead 





11 



do 



Do. 



12... 



...do 



Do. 



13 



do 



Do. 



Total 











2,753 



2,529 



5,282 





■ 1 





It will be noticed from Table IV that most of these scales were 

 removed for dissection upon July 15. These scales were among the 

 most advanced in the orchard. Their exhaustion in the middle of 

 July does not therefore represent the end of reproduction in the 

 orchard, which came much later. 



