254 FOUNDERS OF OCEANOGRAPHY 



organisms of the plankton (excepting the Bacteria) is a 

 culture method devised by Dr. E. J. Allen of Plymouth. 

 By diluting half a cubic centimetre of the sea-water with a 

 considerable amount (1,500 c.c.) of sterilized water treated 

 with a nutrient solution, and distributing that over a large 

 number (70) of small flasks in which after an interval of 

 some days the developed organisms can be counted, he 

 calculates that the sea contains 464,000 of such organisms 

 per litre, whereas the centrifuge showed only 14,450 per 

 litre ; and he gives reasons why his cultivations must be 

 regarded as minimum results, and states that the total 

 per litre may well be something like a million. Thus every 

 new method devised seems to multiply many times the 

 probable total population of the sea and reminds one of the 

 poet Spenser's lament in " The Faerie Queen " : — 



" O what an endlesse worke have I in hand, 



To count the sea's abundant progeny, 



Whose fruitful seede farre passeth those in land, 

 * * * * * 



Then to recount the sea's posterity 



So fertile be the flouds in generation, 



So huge their numbers and so numberlesse their nation." 



The conclusion in regard to this branch of plankton 

 investigation must be that there is probably no one method 

 which can give us a complete quantitative estimate of the 

 total number of organisms in a sample of sea-water ; but 

 by the combination of a number of methods — coarse and 

 fine nets for the larger organisms, centrifuging and cultiva- 

 tion flasks for smaller — we may hope in time to approximate 

 to a solution of the problem, how to obtain a planktonic 

 census of the sea. And even then it wiQ only be the sea at 

 that time and place. 



Therefore, in my judgment, the validity of the conclusions 

 arrived at by the quantitative methods depend too much 

 upon exactly where and when the samples are taken. At 

 another neighbouring locality, or at a different time, the 

 results might be very different. There are, obviously, 



