DISCOVERY REPORTS 



which it makes. This is discussed more fully on p. 240 and illustrated in Fig. 125. The 

 species appears to rise rapidly into the upper layers of the water at the onset of darkness, 

 and during the hours of daylight it sinks out of range of the series of tow-nets almost 

 altogether — below 1 50 or 200 m. This phenomenon, which appears all the more remarkable 

 when we consider the physical and chemical changes met with in the water, makes the 



Fig. 88. Chart showing the distribution of Antarctomysis maxima at stations in the South Georgia December- 

 January 1926-7 survey. The squares represent the numbers taken in three N 100 H nets each towed for one 

 mile at approximately 5, 60 and 120 m. depth respectively. 



study of its distribution very difficult, for to get comparable results all our observations 

 should be made during the hours of darkness. A comparison between Fig. 90, show- 

 ing its distribution as revealed by our nets, and Fig. 89, showing the stations taken in the 

 hours of darkness, will make this clear. We might be inclined to say that it occurred 

 in the largest numbers over the edge of and just beyond the Continental Shelf were not 

 the outermost observations usually taken at night. Since it occurred in comparatively 

 small numbers at the night stations taken on the lines to the west, south-west and south 

 we may conclude that like E. superba it is more abundant off the north-east coast. The 

 distribution of these two species will be further considered in a later part in relation to 

 the principle of animal exclusion. The species, like E. superba, also exhibits a patchiness 



