20I 



THE OLDER STAGES 



scale hatching occurs. This phenomenon is illustrated in Fig. 28, which clearly shows that where- 

 ever substantial numbers of deep rising larvae, Nauplii and Metanauplii, were encountered, they 

 occurred either right on the Antarctic continental slope or in water exceeding 1000 fathoms (1829 m.) 

 at variable distances out to sea. It shows too that wherever these early stages were encountered in 

 the shallower shelf sea areas, they never occurred there other than in negligible numbers. Since the 

 presence of large or small numbers of Nauplii or Metanauplii must indicate at still deeper levels 

 (p. 98) the presence or recent existence of correspondingly large or small numbers of hatching eggs, 

 it seems clear enough that it must be at enormous depths, in the open sea, and not in shelf water, 

 that hatching takes place on the immense scale necessary to maintain this teeming population. 



ACS ANTARCTIC CONTINENTAL SLOPE 



* NO OBSERVATIONS 



Fig. 29. Numbers and vertical distribution of Nauplii, Metanauplii and First Calyptopes, recorded in shelf and oceanic water 

 showing the enormous scale of the hatching that takes place in the deep ocean as compared with the shallower waters bordering 

 the continental land. Note that the numbers plotted above 1000 m. in oceanic water (e.g. 440) represent the total Calyptopis 

 catch for every 4 stations made beyond the slope (see footnote i). 



The relatively enormous scale of the hatching that takes place in oceanic water as compared with that 

 so far discovered in shelf waters is shown more realistically in Fig. 29 which illustrates diagram- 

 matically a shelf sea, such as exists in the Bransfield-Weddell West region, with a continental slope 

 and deep oceanic water beyond. All the larval occurrences from shelf, slope and oceanic water plotted 

 in Fig. 28 are represented on it, the gatherings of Nauplii, Metanauplii and First Calyptopes 

 recorded at each station, or, as for the Calyptopes in oceanic water, every four adjacent stations,^ 

 being shown as indicated in the key. As far as the bathymetric scale has allowed, the stations are 

 arranged so as to appear over the actual depth of water in which they were made. Clearly, as this 

 diagram shows, it is the Antarctic continental slope, and the deep oceanic waters of the East Wind 



1 Owing to the great abundance of First Calyptopes in oceanic water, especially between 750 m. and the surface, the catch- 

 figures for this stage, because of overcrowding, cannot be shown clearly in this diagram for each individual oceanic station. 

 They have accordingly been shown for every four adjacent stations made beyond the slope. 



