l;V2 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



The Ichthyological Committee had evidence from two 

 eminent hydrographers, Dr. H. R. Mill and Captain 

 Tizard, R.N., that both the surface and the deeper 

 layers of water in a shallow area like the North Sea 

 change in character very much, both as regards one 

 place compared with another and the one place 

 compared with itself, at different times. Now, 



quarterly cruises may obviously miss many such changes, 

 and therefore conclusions drawn from the observations 

 may be erroneous. Moreover, il is very doubtful whether 

 the sedentary fiat fish in which we in this country are 

 primarily interested are affected by the conditions which 

 will be observed on the quarterly cruises. For these and 

 other reasons it is evident (1) that the quarterly cruises, 

 as planned in the Christiania scheme, are not sufficiently 

 numerous to give reliable results, and (2) that these 

 hydrographic results, even if obtained, have little or no 

 bearing upon our most important fishery problems. They 

 are also open to the objection that once in three months 

 they take the special steamers away from any particular 

 investigation upon which they may be engaged for a 

 period so indefinite that Captain Tizard estimated it at 

 one week and Dr. Mill at three. 



The international scheme, as laid out in the Christiania 

 programme, is evidently based upon the hypothesis that 

 sound conclusions may be drawn from samples, both 

 hydrographical and biological, taken by the few special 

 steamers making periodic traverses and Surveys over great 

 extents of sea. A consideration of the size of the areas 

 to be covered, of the small number of vessels available, 

 and of the limited time, makes it certain that the samples 

 to be taken will be relatively far apart both in space 

 and time. Now there is much evidence, both in the pages 

 of the Ichthyological Committee's report and also in 



