224 DISCOVERY REPORTS 



'Deutschland', 'Meteor', 'Dana', 'Carnegie', and the B.A.N.Z.A.R.E., to see by how much in each 

 case the catches in high latitudes differed from those in low latitudes. These results must be used 

 with reservation, since they are widely scattered in time and place, and they are derived from different 

 methods and techniques; furthermore, in arriving at the latitudinal means plotted in Fig. 19 no 

 allowance has been made for the east to west variations in standing crop that are known to occur in 

 certain latitudes (e.g. that of the Sargasso Sea). 



100.000 



in 



a 





2 

 u) 

 5 50.000 



< 

 o 

 a. 

 O 



ID 



* IO.OOO 



Z 



NANNOPLANKTON 



METEOR 



a. 

 O 



a 



DEUTSCHLAND 



NET PLANKTON 



IO.OOO 







X 



a. 



Ui 



z 

 < 



,0, 



5.000 



-1 r 



DISCOVERY 



> R 



> m 



CARNEGIE 



I — 



o 



NORTH 70 



60 



40 



I 

 o 



30 



20 



~l 



o 



10 



30 



40 



50 



70 SOUTH 



Fig. 19. The results of other expeditions compared with the summer mean total volumes (1000-0 m.) previously 

 described in fig. 10. The few B.A.N.Z.A.R.E. results are indicated by a x . Sources of data are given below. 



Fig. 19 and Table 10 compare the results of all the expeditions with the latitudinal variations in the 

 1 000-0 m. summer volumes which have been previously discussed in greater detail (p. 214 and 

 Fig. 10). It should be noted that the vertical scale is different for the results of each expedition, as are 

 the units in which some of them are expressed. The sources of the data are summarized below. 



The Deutschland (Lohmann, 1919, table 6, p. 16) and Meteor results (Hentschel, 1936, table 4, 

 p. 8) both refer to the numbers of nannoplankton organisms in 1 1. of sea water in the upper 50 m. 

 (i.e. the mean of the o and 50 m. catches). As the observations are confined to the euphotic layer the 

 counts must comprise at least 50 per cent phytoplankton and so are not strictly comparable to the net 

 plankton catches of the other expeditions which consist principally of zooplankton. For this reason 

 in Fig. 19, the Deutschland and Meteor results have been considered separately from the other data. 



