326 DISCOVERY REPORTS 



Scotia Sea and South Georgia, December 1931 (Fig. 20, Table VI b) 

 On the line of Sts. 751-759 (Western Scotia Sea), at the beginning of December, con- 

 ditions were much the same as on the line of Sts. 743-750 at the end of November (Eastern 

 Drake Passage). Stage v still predominated and the proportion of adults was high, 

 except at St. 753. 



Early in the season, during the month of November, many of the stations show a high 

 proportion of adults in the upper nets (Sts. 727, 735, 737, 741), and at some others, 

 notably Sts. 726 and 739, the proportion of adults was approximately equal in both the 

 upper and lower nets. In those, however, which were taken after the end of November 

 and in early December in the Drake Passage and Western Scotia Sea (Sts. 743-761), the 

 proportion of adults is higher in the lower hauls than in the upper. This, it has been 

 suggested (pp. 321, 322), may represent a descent of the adult females to a fertilization 

 level coincident with the appearance of a high percentage of adult males in the layers 

 below 100 m. 



At the end of the first week in December (St. 763) stage vi (adults) began to pre- 

 dominate in the catches. The appearance of the stock curves for the lower hauls at Sts. 

 763-768 and 775 is perhaps partly due to the appearance of large numbers of adult males 

 in the lower hauls (Table N a). In the upper hauls at these stations, however, adult 

 females were overwhelmingly predominant. Sts. 763-768 were taken in water flowing 

 out of the Weddell Sea, so that it is possible that the population at these stations is a 

 mixed one, consisting partly of the stock from the Drake Passage and partly of that 

 from the Weddell Sea. At Sts. 774, 775 and 776, which were taken in the Bellingshausen 

 Sea current, unmLxed with water from the Weddell Sea, the stock is approaching 

 maturity, but contains more stage v than that at the stations in Weddell Sea water south 

 of South Georgia. At St. 776, immediately north of the convergence in this area, there 

 is a surprisingly high proportion of stage iv in the surface haul. 



South Atlantic Ocean, East of South Georgia, mid-December 1931 to 

 mid-January 1932 (Fig. 21, Table VI c) 

 The stations east of South Georgia, taken in the middle of December and the middle 

 of January, appear to show several different stocks. Firstly there is a stock consisting 

 almost entirely of young forms up to stage iii. These are found at South Atlantic stations 

 in water of Bellingshausen Sea origin (Sts. 796, 802 and 803). In addition to these three 

 stations there is St. 778 (18. xii. 31) at which we find two age groups in the surface haul 

 — an old one consisting of stages v and vi and a young one consisting of nauplii, stages i, 

 ii and iii. The surface net at this station was choked with diatoms so that it is not im- 

 possible that it took an unduly high proportion of very young forms. On the other hand, 

 at St. 780, taken the next day in Weddell Sea water, the surface net was similarly choked 

 with diatoms and no young forms were taken at all. Abundant diatoms were also taken 

 in the i-m. nets at several other stations at this time (Sts. 806, 807, 808 and to a lesser 

 extent 809), but in these again no very young forms were taken. The presence of nauplii 

 and very young stages at St. 778 may therefore legitimately be taken to indicate that 



