THE OLDER STAGES 189 



It is evident then, from the data so presented, that neither pairing, as shown by the vertical dis- 

 tribution of the spermatophore-carrying males and females, the stages recognised by Bargmann (1945) 

 as 6 and 7 in males and 6 in females, nor spawning, as shown by the vertical distribution of the gravid 

 and spent females (Bargmann stages 7 A and 7B), can be described as anything other than a surface 

 phenomenon.^ In other words, as might be expected, there is nothing to suggest that the vertical 

 distribution of the breeding adults is in any way different from that of the whale food as a whole. 

 It might, however, be argued that spawning takes place in the still greater depths that as yet remain 

 unexplored, in the great deeps where it seems (p. 98) the eggs themselves are hatching. While this 

 is a possibility that cannot be ignored our failure to capture anything but negligible numbers of spent, 

 gravid or recently paired females at intermediate depths seems to point to its at least being improbable. 

 For if the gravid females go to such enormous depths to shed their eggs, unless they do so so widely 

 scattered as virtually to defy capture even by our largest nets — a wholesale scattering which while 

 possible is wholly inconsistent with the Hfelong swarming habit (p. 230) to which this species seems 

 prone — it is astonishing that not one of our hundreds of towings, many of them with nets of the largest 

 size, worked below 100 m. during the spawning season^ has yet revealed the slightest evidence of a 

 concentration of them on their way from the surface down. 



Localities of spawning 



In so far then as it can be gleaned from the vertical distribution of the ripe or spent females the 

 evidence in favour of deep spawning in oceanic water is to all appearances negative. At the same time 

 the evidence in favour of large-scale oceanic surface spawning, although apparently positive in so far 

 as the vertical distribution of the spent and gravid females is concerned, is patently contradicted it 

 seems (Fig. 19) by the vertical distribution of the eggs themselves, the numbers of the latter 

 recorded in the Antarctic surface layer being far too small to warrant the conclusion that it is there, 

 near the surface, that spawning over deep water is actually taking place. Although females then 

 apparently ready to spawn and females that have in fact spawned are both encountered near the 

 surface in oceanic water we cannot altogether disregard the possibility that of the gravid, or apparently 

 gravid, and spent females recorded there, the former may fail to reach the actual point of spawning 

 while the latter it seems might have laid their eggs in some other and possibly distant place. While it is 

 difficult to judge from these contradictory appearances what is in fact taking place in or over deep 

 water, it seems that, in so far at least as the major aspects of the spawning are concerned, the open 

 sea can be playing at most only a secondary part. It is suggested, therefore, that the enormous annual 

 output of larvae necessary to replenish the whale food population may have its origin somewhere in or 

 near the coastal water of the Antarctic continental land where as already seen (p. 168, Fig. 19) 

 the second largest of the only two major concentrations of eggs to be recorded was originally found 

 and where one of our only three major occurrences of a recent product of hatching, the Second 

 Nauplius, was encountered (p. 93, Table 14, Station 2603) very close to the bottom. Moreover, the 

 fact that we have repeatedly struck the eggs with far greater frequency in or near the shelf water of 

 continental Antarctica than we have in the open sea provides further ground for supposing that it must 

 be in the coastal or near-coastal waters of high or relatively high latitudes that spawning is principally 

 taking place. In the shelf and slope waters of the Bransfield Strait, North Graham Land and the 

 East Wind zone 98 stations were made, covering, if all the years these investigations have lasted be 



1 From the pronounced abundance of paired females he finds in whales' stomachs Nemoto (1959) also concludes that the 

 krill copulate on the surface. 



^ Expressed in terms of i-m. diameter stramin nets the actual number so worked in the period November to March was 

 384- 



