I30 DISCOVERY REPORTS 



dividing cells as in the active stage. Spermatozoa are to be found in varying numbers in 

 all the stages, and not always in the greatest numbers in the most active stage, which is 

 characterized more by the intensity of cell division than by the presence of quantities of 

 fully developed spermatozoa. Spermatozoa are not present in striking numbers at any 

 stage, but they appear to be present more frequently and in greater quantity than in the 

 corresponding states found in the Whalebone whales. The results of the histological 

 examination of the material of the present series of whales are here presented in detail 

 according to the season of the year and the state of activity of the testis. 



January. South Georgia 



No. 2994. Length 17-50 m. 15. i. 30. Active, all tubules well filled with cells and without spaces, 

 but not many spermatozoa present. 



No. 301 1. Length 15-60 m. 21. i. 30. Intermediate, tubules with very large central spaces, but 

 nearly all with a fair number of spermatozoa. 



February. South Georgia 



No. 3654. Length 15-06 m. 14. ii. 31. Active, smears prepared from testis and epididymis both 

 showed many spermatozoa. 



No. 3129. Length 16-57 "i- i°- '■• 3°- Active, tubules fairly full of cells, but some with small 

 central spaces. Spermatozoa plentiful. 



No. 3170. Length 15-15 m. 27. ii. 30. Active, but less so than No. 3129. Tubules similar but 

 spermatozoa scarce. 



No. 3130. Length 16-53 "i- i°- ''■ 3°- Intermediate, most tubules with fairly large spaces. 

 Spermatozoa present in fair numbers. 



No. 3171. Length 15-35 "i- 27. ii. 30. Intermediate, very similar to No. 3130, but spermatozoa 

 almost absent. 



March. South Georgia 



No. 1756. Length 15-45 m. 28. iii. 28. Active, tubules large and closely packed with cells, no 

 spaces. Spermatozoa numerous. 



No. 2479. Length 14-91 m. 19. iii. 29. Active, tubules as No. 1756. Spermatozoa abundant. 



No. 2480. Length 14-52 m. 19. iii. 29. Active, tubules well filled, but many with spaces. Sper- 

 matozoa moderate in numbers. 



No. 1752. Length 14-38 m. 27. iii. 28. Active, tubules well filled, but many with fairly large 

 spaces. Spermatozoa numerous. 



No. 2478. Length 14-14 m. 19. iii. 29. Intermediate, nearly all tubules with fairly large spaces. 

 Spermatozoa not very plentiful. 



No. 3193. Length 15-00 m. 7. iii. 30. Resting, tubules with large spaces. Spermatozoa very few. 



No. 1606. Length 14-90 m. 29. iii. 27. Resting, tubules with very large spaces. Spermatozoa 

 practically absent. Part of this testis, however, was composed of typically immature tissue. 



April. South Georgia 



No. 1759. Length 15-17 m. 2. iv. 28. Active, all the tubules tightly packed with cells. Sper- 

 matozoa fairly numerous. 



No. 1769. Length 15-95 "^- ^9- i^- 28. Active, most of the tubules tightly packed, though some 

 were completely empty. The empty tubules may be the result of an accident in manipulation, but the 

 preparation shows no signs of bad fi.xation. Spermatozoa plentiful. 



No. 1758. Length 15-82 m. 2. iv. 28. Active, all the tubules fairly well filled though most of them 

 have small central spaces. Spermatozoa fairly plentiful. 



