342 DISCOVERY REPORTS 



part very small, numbers are encountered from late April to June, they evidently do not appear in 

 any substantial measure of abundance until July. 



(3) While we have no evidence of any large-scale incursion of these stages into the Bransfield Strait 

 or the South Georgia whaling grounds in March and April, it seems clear, particularly from the 

 evidence of Hansen (1913), that in the latter locality at least they must have arrived in substantial 

 numbers by about May. 



(4) The East Wind drift is barren of late Furcilias throughout March and April and it is probably 

 not until some time after June that they first begin to appear there on any appreciable scale. 



(5) From July onwards the facts of the distribution can only be determined with certainty for such 

 northerly areas of larval abundance, that is, the Weddell drift and the South Georgia whaling grounds, 

 as continue to remain unaffected by the encroachment of the winter ice. In both regions the mass of ] 

 the larvae in the plankton now consists exclusively of late Furcilia forms. By mid-July the Sixth 

 Furcilia has become dominant and in general remains so throughout August until about mid- 

 September. From then onwards the early adolescents become increasingly the more abundant, the j 

 Sixth Furcilia becoming very scarce towards the end of November and finally disappearing from the 

 plankton (of the northern ice-free zone) in December. Largely, however, owing to the late arrival in 

 Weddell East of the Calyptopes that spring from the March risings in Weddell Middle the Sixth 

 Furcilia may occasionally be encountered dominant in the far eastern reaches of the current through- 

 out September and into early October. 



(6) The West Wind drift, as far at least as the vertical nets can show, is barren of late Furcilias j 

 except again for such parts of it as are affected by tongues of cold water emanating from the East Wind 

 zone. In such tongues Furcilias 4-6 are probably to be encountered most frequently and in greatest j 

 abundance from May to September. 



(7) No late Furcilias have been recorded in the Pacific sector, though here it has been largely! 

 the West Wind drift only that has been sampled in the months in which these stages might be 

 expected. 



(8) Finally, it will again be noted how both slow growth and ice conditions in the East Wind zone I 

 combine to render the presence of the late Furcilia population in these high latitudes virtually | 

 impossible to disclose. 



Total eggs and larvae and total surface larvae 



The bi-monthly distribution and relative abundance of the total eggs and larvae (the latter com- 1 

 bining both deep and shallow living forms) from November to April is shown in Figs. 97-99, 

 corresponding illustrations for the total surface larvae (the shallow living forms in the top 250 m.) 

 from January to June being shown in Figs. 100-102. The distribution and relative abundance of] 

 the total surface larvae for the periods November-December, July-September and October-December j 

 (p. 309, Fig. 73; p. 336, Fig. 93 and p. 337, Fig. 94) have already been shown. 



These nine charts serve principally to summarise the more important features of the larval distribu- 

 tion, and the factors controlling it, and in general to reinforce such conclusions as have already been I 

 drawn. The following is a summary of the principal facts they reveal : 



(i) The early, November-December, beginnings of the larval life-cycle in Weddell Westj 

 (Fig. 97), notably in the far western reaches of that sector of the current. 



(2) The improbability, clearly suggested by the concentration of the total surface larvae in Weddell j 

 West in January-February (Fig. 100) that there can be simultaneous beginnings occurring all[ 

 round Antarctica under the winter ice-sheet which in November-December still covers an enormous ' 

 area of the circumpolar sea. 



