364 DISCOVERY REPORTS 



In the northern or Weddell zone the major features of the autumnal condition may be summarised 

 as follows: 



(i) The last few risings having finally been accompUshed in April (p. 321, Fig. 82, Stations 

 WS 197, 2346) surface swarms with a First Calyptopis mode have become exceedingly rare and have 

 disappeared altogether by the end of the month. 



(2) Throughout the season the most frequently encountered dominants are the Third Calyptopes 

 and the early Furcilias, the former predominating during the first half of April, the latter from about 

 the middle of April onwards. 



2 3 4 14 14 14 14 15 IS 16 16 17 19 202I 22232626 27 27 27 27 2B2830 12 3 4 2728! '2358899 I024 24 



W529 1331 383 2316 2318 2320 WI98 W200 1346 2344 1351 2346 1352 1354 1356 887 1779 1782 I790 1792 1794 2843 



198 383 2316 2318 2320 W197 W199 W201 I350 861 2346 862 1353 1355 1357 888 1781 1785 1790 1792 912 



6 

 5 

 4 

 3 

 2 

 I 



3 

 2 

 J 



N9 EXAM- 

 INED 



APRIL 



MAY 



JUNE 



ITtf^iflfU^^^' 



FURC 6 I I— T— I DEPTH I I 



r I^H T^II ° so lOO ^H^H so loo 



90 68 168 209 220 167 26 154 84 34 100 63 lOO 100 80 56 26 28 90 79 201 17 

 72 620 I057 532 158 64 45 19 177 230 169 72 72 100 143 25 162 344 79 289 1480 



6 FURC 



5 



4 



3 



2 



I 



3 CAL 



2 



N? EXAM- 

 -INED 



Fig. 113. Developmental condition of the massed surface larvae in autumn. For East Wind zone see Fig. iii. 



(3) The autumnal scarcity of late Furcilia dominants, which seems anomalous in view of the already 

 well established existence of such dominants (p. 361, Fig. iii) in Weddell West in the latter part 

 of March, is probably to be ascribed to the fact that the majority of our April observations in Weddell 

 West were made in two seasons when there seems to have been a marked decline in the activity of the 

 Antarctic bottom water resulting (p. 331) in a late arrival of deep larvae in Weddell West and a 

 correspondingly late development to the older Furcilia state. 



(4) As expressed by the stage frequency the modal values of the autumnal swarms display a highly 

 heterogeneous pattern. 



In the East Wind zone the April swarms (Fig. iii) continue to reveal a much retarded develop- 

 mental condition, the First Calyptopis remaining still virtually the only dominant surface stage. Now 

 it is true it is being encountered more frequently, and increasingly, in moult, in one instance 

 (Station 854) the Second Calyptopis having become slightly dominant. The continuance of the First 

 Calyptopis as virtually the sole dominant in these high latitudes until so late in the year is perhaps 

 not surprising when it is recalled that at two of the three stations (p. 93, Table 14, Stations 854 and 

 855) where we struck the larvae there extensive risings were still taking place. 



Winter. Thus far it will have been seen, that is from January up to the end of June, we have been 

 dealing with a heterogeneous assemblage of purely larval swarms yet to become adolescent, swarms 

 in which the developmental condition has been determined by staging alone. From July onwards, 

 however, although some purely larval swarms remain, notably in the Weddell zone throughout July 

 and August, the young swarms in most instances consist of mixtures of larvae and adolescents, the 

 former, gradually losing their dominance, persisting in the Weddell drift until the end of November 

 (p. 339),^ in the East Wind outflows until December (p. 368) and in the East Wind drift itself over 

 December into March of the following year (p. 355). With such mixtures staging alone cannot present 

 the whole developmental picture, for it would merely amount to separating the swarms into their late 



* See again, however, p. 338, note i. 



