THE AGE OF FEMALE BLUE WHALES 



FI.F. ' Tafelberg' 



249 



Number of whales considered in table 



„ in sample whose only recent corpus is of pregnancy 



„ in sample non-pregnant with no recent corpora 



„ in sample ... 



34 

 20 

 62 



collections from several factories were treated in this way and are included in the list. 

 When results are given as percentages or averages, they are based on the ovaries in the 

 list and not on all ovaries from the ship in question. 



In the list are shown, for whales over 81 ft. long, the length of the whale, total number 

 of corpora lutea, the presence or absence of a corpus of pregnancy, the number of 

 new corpora, their mean diameter, and the diameter of the largest old corpus in each 

 case. It will be seen that there is mostly a difference of at least 2 cm. between the 

 smallest recent corpus albicans and the largest obviously old one. The difference in 

 volume is, of course, much greater, since the volume is a cubical function of the 

 diameter. 



There are three classes of whales in each of these collections, except that from the 

 'New Sevilla': pregnant, recently ovulated but not pregnant, and resting whales which 

 do not appear to have ovulated at all during the previous winter. The range of recent 

 ovulations in this material is three to five, but the majority showed one, two, or three. 

 The average number of recent ovulations shown by whales with corpora lutea of 

 pregnancy is as follows: 



4-2 



