6 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



ago, these Laboratories in which we are now assembled, 

 alluded to the absence of exact knowledge of the subject 

 which he found on taking office as President of the Board 

 of Agriculture and Fisheries. Of course, isolated facts 

 of a quantitative nature had become known and were 

 accumulating, but there was no organised body of 

 quantitative data such as would suffice to guide a policy 

 or lead to definite conclusions on many fishery questions. 

 As an unimportant example of such an isolated obser- 

 vation we may take the fact that about twenty millions of 

 the minute organism Ceratium tripos may be eaten in one 

 day by the sardine on the French coast. No doubt every 

 fact in science is of some value, and will one day find its 

 place in the completed scheme of knowledge. But as a 

 single observation unrelated to other facts this is of 

 comparatively little value, except in so far as it suggests 

 to us how important it might be to find out when, where 

 and why the Ceratium becomes available as food for the 

 sardine, where it comes from, and why it is sometimes 

 absent. Many attempts have been made of recent years 

 to answer such questions by obtaining quantitative 

 information as to the distribution of organisms in the 

 sea. The, most noteworthy example of such work is that 

 done by the Grerman k ' plankton " naturalists, such as 

 Hensen, Brandt, Lohmann and Apstein, at first under 

 the well-known '* Kiel Commission," and latterly in 

 connection with the International exploration of the 

 North Sea. These investigators, and especially Professor 

 Hensen, deserve the greatest credit, not only for the 

 central idea of organising and employing such means 

 as would give exact quantitative results, but also for the 

 ingenuity with which they have devised and worked out 

 the details of the necessary methods and instruments. 

 They have invented deep-water tow-nets, the silk of which 



