THE AGES OF WHALES 



451 



mature and really belong to Group 2. Group 2 may be taken as including whales with 

 from nine to fifteen corpora lutea. Pregnant whales in this group will have been adult 



T — I — I — I — 1 — I — 1 — r 



5 10 



NUMBER OF CORPORA LUTEA 



Fig. 156. Blue whales. Frequency of numbers of corpora lutea. 



.X" 



-1 — r 



-| — I — I — I — r 

 35 



1 — I — I — r 



I I ' I I I ■ 

 5 10 



NUMBER OF CORPORA LUTEA 



I ' ' 

 15 



I I ' 

 20 



I I 

 25 



1 — T 

 30 



Fig. 157. Fin whales. Frequency of numbers of corpora lutea. 



for three seasons, and lactating whales for four seasons. The remaining whales— those 

 with sixteen or more corpora lutea — are presumed to be more than five years old. 



Applying this grouping to the female Blue whales of South Georgia and South 

 Africa we get the following analysis of the catches : 



25-2 



