36o DISCOVERY REPORTS 



indication of the presence of the larger larvae than the smaller finer-meshed N70V. While it retains, 

 as I have repeatedly noted, an abundance of forms ranging from the Third Calyptopes upwards, and 

 occasionally, if present in exceptionally large numbers an abundance of Second Calyptopes, for the 

 most part it appears to allow the First Calyptopis to escape through its meshes. Thus while the First 

 Calyptopis was dominant at East Wind Stations 854 and 855 (p. 93, Table 14) in the upper (250-0 m.) 

 vertical nets, the obUque stramin nets fished through the same horizon at these stations showed 

 (Fraser, 1936, p. 138) the Third Calyptopis as the dominant stage with the First Calyptopis not even 

 represented. It is, therefore, not surprising that while the coarser net, as Fig. no shows, provides 

 the most striking evidence of the great larval outburst which takes place in Weddell West in summer, 

 by the end of which many of the larvae (p. 331, Fig. 90) have reached a dominantly Fifth 

 FurciUa stage, it should fail almost entirely to disclose the contemporary existence of the much 

 younger First Calyptopis population the vertical nets reveal (p. 321, Fig. 83) in the surface waters 

 of the East Wind zone. The extreme scarcity of older stages in the far southern nets provides, more- 

 over, corroborative evidence that the young East Wind swarms have not as yet advanced materially 

 beyond the First Calyptopis stage and adds further weight to the evidence, already provided by the 

 vertical nets, that the larval growth-rate in these high latitudes is indeed exceedingly slow. 



Turning now to the main facts of the summer distribution of the massed larval forms, it will be 

 seen that in the principal region of their abundance in the north the vast majority are concentrated 

 in Weddell West with some slight overflow into Weddell Middle, an overflow which somewhat 

 surprisingly does not extend so far east as that revealed (p. 197, Fig. 27) by the vertical nets. 

 The discrepancy, however, can again be explained in terms of the selectivity of the apparatus in use, 

 the most easterly surface occurrence of larvae disclosed by the vertical nets (p. 313, Fig. 76, 

 Station 1 144) having consisted almost exclusively of First Calyptopes, too small it seems to be retained 

 by the stramin net. Beyond the principal scene of concentration in Weddell West, the heavily 

 sampled South Georgia whaling grounds, apart from a single minor occurrence^ (a March record), 

 are virtually barren of the young surface swarms suggesting again that it is not in fact until autumn 

 (p. 330) that the larvae carried in the surface stream first begin to arrive there on any substantial 

 scale. In the Bransfield Strait, also heavily sampled, no larvae are recorded, suggesting that in this 

 locality too the earliest large-scale incursions of young stages borne in the drift from the 

 Bellingshausen or Weddell Sea do not take place (p. 363, Fig. 112) until later in the year. There 

 are three minor occurrences in the West Wind region of the Scotia Sea. All, it is possible (p. 327), 

 might have come from far south in the Bellingshausen Sea or from the richly populated Weddell West 

 region immediately to the south. Elsewhere the West Wind drift is barren, not only in its warmer 

 parts, but also in the several localities where it is affected by cold outstreamers from the East Wind 

 zone. The absence of larvae in the outstreamers, however, need not in this instance be accepted 

 as real, for it has already been shown (p. 311, Fig. 75 and p. 326, Fig. 87, Station 2280) that 

 in an area such as that affected by the northward flow near Peter I Island a substantial population 

 of surface larvae may by March already be established, although no doubt such populations, should 

 they occur simultaneously in cold tongues elsewhere, would, like the population at Station 2280, 

 normally be too young to be sampled by the stramin net. 



The conspicuous density of negative observation in the Pacific sector up to the highest latitudes 

 we have penetrated (and here there are moderate numbers of samples from the East Wind zone) 

 leaves little doubt that in so far as the larvae are concerned this is the most barren and least productive 

 region of the circumpolar sea, suggesting strongly that, apart from the spawning that evidently takes 



1 Hardy and Gunther (1935, Appendix 11) also record two minor occurrences of larvae ('Cyrtopias' = possibly Furcilias) 

 from the plankton survey of this region that took place in March 1926. 



