STATISTICS OF CATCHES 227 



In an unpublished note on the growth and age of Blue and Fin whales which was 

 submitted to the International Whaling Conference of 1939, Dr N. Peters considered 

 that an old corpus luteum of pregnancy could be distinguished histologically from one 

 formed from a corpus luteum of pseudo-pregnancy (i.e. of ovulation which has not been 

 succeeded by impregnation). By counting the former and assuming a two-year repro- 

 ductive cycle, he provisionally estimated that in the Blue whale there is an average of 

 1 "Q and in the Fin whale an average of i-8 ovulations in two years. This is not much 

 different from Laurie's estimate for Blue whales. 



Recently, a very important whale mark was returned to the Discovery Committee 

 which had been carried by a whale for six years and which throws some light on the 

 rate of accumulation of the corpora lutea. It was fortunately recovered in the factory 

 ship ' Svend Foyn ' in the season in which Mr P. R. Crimp was examining whales on 

 board, and he was able to secure the ovaries. Particulars are as follows : 



Mark no. 696. Fired: 11. xii. 34; 54 45' S, 34 51' W (off South Georgia). 

 Recovered: 26. ii. 41 ; 6o° 15' S, 54 22' W. 



Whale: Fin, female, 23-2 m. (76 ft.), not pregnant. 



Ovaries : 4 lb. 9 oz., with eight old corpora lutea. 



Uterus: 16 cm. (collapsed diameter). 



Mammary glands : 5 cm. thick, involuted. 



Vertebrae : epiphyses unfused. 



Scars : moderate number. 



No note as to the whale's size was made at the time of marking, so there is no reason 

 to suppose that it was then conspicuously immature. One cannot draw any final con- 

 clusions from the particulars of a single whale, but in this one, since it had only eight 

 corpora lutea, the rate of accumulation cannot have been much more than about one 

 a year (or two every two years), and, since there was no clue to the whale's age at the 

 time of marking, the rate of accumulation may have been even slower. This is compatible 

 with Peters's estimate for Fin whales but hardly with Wheeler's. 



It may be that some definite conclusion as to the rate of accumulation will be reached 

 when all the data on ovaries can be examined. 



STATISTICS OF CATCHES 



The statistics of the whaling industry provide essential information on the industry 

 itself and on the stock of whales. Whaling factories of nearly all nationalities are required 

 to keep records of the species, length, sex, date and place of capture of every whale 

 taken, and, so far as possible, of the length and sex of any foetus present. Information is 

 also supplied as to the number and tonnage of the ships employed and the production of 

 oil and other commodities. The figures are tabulated and analysed by the Committee for 

 Whaling Statistics appointed by the Norwegian Government on the recommendation 

 of the International Council for the Exploration of the Sea. Since 1930 this Committee 

 has published annually an analysis of the statistical data (those from the Antarctic and 



