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more times as many individual cells in one haul as in another, 

 but all will be in the tens, or in the hundreds, or the 

 thousands, or millions. For example, on April 3 we have : — 



Coscinodiscus radiatus, 1,600, 2,600, 2,600, 2,800, 2,800, 

 2,200. 



Streptotheca thamensiSy 40, 30, 30, 40, 40, 60. 

 Many other similar examples might be given from the 

 detailed records, but on the other hand other occasions 

 show more variation. 



It is much the same with the four common species of 

 Dinoflagellates recorded. There again we find cases of 

 considerable constancy in the hauls of a series, such as : — 



May 25. Peridinium divergens, 46,000, 62,000, 50,000, 

 44,000 ; 

 and other cases of more variation, even in that same series, 

 such as : — 



May 25. Ceratium furca, 6,000, 2,000, 8,000, 1,000. 

 Are we entitled from this to conclude that the Peridinium 

 is evenly distributed through the zone of water sampled 

 and the Ceratium much less so ? I doubt it. 



The Copepoda seem also to indicate in many cases a 

 fairly even distribution. Sometimes they occur only in 

 units, and yet each haul of the series shows a few : — 



April 3. Oithona similis, 8, 4, 3, 3, 5, 11. 



April 13. Temora longicornis, 10, 5, 10, 10, 10. 



April 13. Oithona similis, 20, 20, 20, 20, 20. 



Other cases; again, seem to indicate considerable variation 

 in adjacent hauls. Which of these contradictory impressions 

 received from an inspection of the results of the hauls is 

 true to nature ? If the Oithonas on April 13 had been 

 very irregularly scattered through the water; is it likely 

 that we could catch exactly 20 in each of five successive 

 hauls ? On the other hand, if they are evenly distributed, 

 how can we account for one haul (April 6) catching 40 

 and the next 140, or for the series on May 25 : — 20, 80, 460, 

 290, in the four successive hauls ? 



