THE AGE OF FEMALE BLUE WHALES 



247 



these recognized forms, I noticed, unfortunately only towards the end of the ovary 

 examination, the occurrence of large regressing corpora, whose substance was soft and 

 fairly well vasculated, and whose pinkish appearance seemed to indicate that they were 

 corpora lutea of ovulation which had existed for a relatively short time. The diameter of 

 these bodies ranged between 6 and 10 cm. (that is the mean diameter, for the bodies 

 were seldom spherical but usually of ellipsoid shape). There is a fairly large difference 

 between the diameter of the smallest of these bodies and the largest of the palpably 

 older ones. 



After this special kind of corpus luteum had been noticed, a few newly mature whales 

 appeared with corpora which must have been of recent production. They are listed below. 



These corpora were identical in appearance with those which I had classed as new in 

 the ovaries of older whales. 



Lists of the ovaries in which these bodies were found are here given according to 

 factories for the season 1935-6. The list could have been much greater if the importance 

 of the bodies had been realized sooner, but the idea of measuring the corpora arose late 

 in the examination of the ovaries, so that all the material is not included in these lists. 

 Barrels were dealt with in the order of their arrival, and it thus happens that part of the 



Fl.F. ' Hektoria' 



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 ... 



12 

 15 

 35 



