I9II] ICE STRUCTURE 217 



there was much drift — now the drift has gone but the gusts run 

 up to 6^ m.p.h. 



Had a comfortless stroll around the hut; how rapidly things 

 change when one thinks of the delights of yesterday! Paid a 

 visit to Wright's ice cave; the pendulum is installed and will 

 soon be ready for observation. Wright anticipates the possi- 

 bility of difficulty with ice crystals on the agate planes. 



He tells me that he has seen some remarkably interesting 

 examples of the growth of ice crystals on the walls of the cave 

 and has observed the same unaccountable confusion of the size 

 of grains in the ice, showing how little history can be gathered 

 from the structure of ice. 



This evening Nelson gave us his second biological lecture, 

 starting with a brief reference to the scientific classification of 

 the organism into Kingdom, Phylum, Group, Class, Order, 

 Genus, Species; he stated the justification of a biologist in such 

 an expedition, as being ' To determine the condition under which 

 organic substances exist in the sea.' 



He proceeded to draw divisions between the bottom organ- 

 isms without power of motion, benthon, the nekton motile life in 

 mid-water, and the plankton or floating life. Then he led very 

 prettily on to the importance of the tiny vegetable organisms as 

 the basis of all life. 



In the killer whale may be found a seal, in the seal a fish, 

 in the fish a smaller fish, in the smaller fish a copepod, and in the 

 copepod a diatom. If this be regular feeding throughout, the 

 diatom or vegetable is essentially the base of all. 



Light is the essential of vegetable growth or metabolism, 

 and light quickly vanishes in depth of water, so that all ocean 

 life must ultimately depend on the phyto-plankton. To discover 

 the conditions of this life is therefore to go to the root of 

 matters. 



At this point came an interlude — descriptive of the various 

 biological implements in use in the ship and on shore. The 

 otter trawl, the Agassiz trawl, the ' D ' net, and the ordinary 

 dredger. 



A word or two on the using of ' D ' nets and then explanation 

 of sieves for classifying the bottom, its nature causing variation 

 in the organisms living on it. 



From this he took us amongst the tow-nets with their beauti- 



