356 DISCOVERY REPORTS 



diagram with the stage frequency, where determined, above. We have no precise stage frequency data 

 covering this period from the East Wind zone. The Sixth Furciha, however, was recorded surviving 

 there at Stations 2547, 2560, 2561 and 2562 in January, and at Stations 2600 and 2603 in March. 



It will be seen then that whereas in the Weddell swarms the peak length frequency or modal value 

 in November (Station WS 487) stands at 17-20 mm., the corresponding value in the East Wind zone 



MONTH 



SEPTEMBER 



DATE 

 STATION 

 ADOLESCENT 

 RJBCIUA 6 



32 ^ 



30 O 

 28 O 



28 28 29 29 29 

 W26I W263 W256 W267 W258 



13 17 17 17 18 IB 19 19 4 4 4 5 5 5 6 5 

 W275 W279 W280W282 W283 W285 W286 W287 W288W295 W296 W297 W299 W300 W30I W302W303 



IIITTIfllTTTTfTTI 



26 5 



2* ^ 



22 ^ 



20 - 



18 S 



16 5 



14 °^ 



.2 X 



10 « 



6 i^ 

 b 



Scale p«r cent 



O 50 lOO 



UUtjUtt+itt 



* * * * 



. O so 100 



****** 



MONTH 



DATE 

 STATION 

 ADOLESCENT 

 FURCILIA 6 



" g 

 30 " 



a 



26 I 



24 « 



22 Z 



re " 



16 < 

 cr 

 14 



12 J 



10 g 



8 UJ 



6 



6 7 7 8 



W304 W305 W306 W3I0 



Sca le per cent 



o so lOO 



* * * * 



22 23 23 25 26 27 29 

 472 481 483 484 487 488 491 492 494 500 502 503 507 511 517 518 523 



ITTTT1TTTTT"T 



* SWARMS IN OR CLOSE TO ICE 



Fig. io8. Developmentarcondition of young first-year swarms on the South Georgia whaling grounds, showing the 

 backward state of those encountered in or near the ice (For vertical scale see legend to Fig. 107). 



a month later (Station RS 9)^ is still only 9-12. It seems obvious, therefore, that since the Sixth 

 Furcilia at Station WS 487 was represented by some 10% of the total larval and adolescent stock, 

 this, the last larval stage, must have been surviving clearly dominant (cf . Stations WS 267 and WS 285) 

 in the young swarm recorded at Station RS 9. And this being so it seems probable that, were it 

 possible to penetrate into high East Wind latitudes to show it, the Sixth Furcilia would be found 

 surviving in the young first year swarms pre-eminently dominant up to the end of November, and 

 possibly still dominant, but surrendering its dominance to the adolescent, in December. 



It would seem, therefore, that in these high latitudes, taking the mid-February rising off the Princess 

 Martha Coast (p. 310, Fig. 74) as the starting-oif point for the development, the life-cycle of the 

 larva in the surface takes upwards of 9 months or more to complete. 



^ This is the only observation we have as to the spring condition of the young swarms in the East Wind zone. It was 

 obtained (p. 255, note i) from a factory ship. 



