JETSAM 



IN spite of many disappointments, there is always a 

 mild excitement in a walk along the shore especially 

 after a storm. One never knows what one may discover 

 among the jetsam the rubbish, as some people would say. 

 But this is to miscall the jetsam, for although there is some- 

 times an element of rubbish the debris of civilisation 

 the uninviting word is seldom appropriate in reference to 

 the whole. What we mostly find is the wreckage of life 

 creatures that have been torn from their moorings, or that 

 have been forced by currents into the grip of the incoming 

 tide, or that have been battered to death and then swept 

 ashore. The jetsam differs greatly at different seasons 

 and in different localities, but it may be of interest to take 

 a representative sample. 



The sand is sometimes mixed with dead or dying 

 Foraminifera (chalk-forming unicellular animals), such as 

 the beautiful Polystomella, which is like a microscopic 

 miniature of a Nautilus shell an instance of that con- 

 vergence of architecture which we often find among un- 

 related forms at very different levels in the animal kingdom. 

 This Polystomella, which we can sometimes see as a white 

 speck on the freshly dislodged seaweed, is a good illustration 

 of the relative nature of simplicity. It is a single cell, a 

 unit of living matter, but it is structurally very complex 

 in comparison with a drop of white of egg. It has a spiral 

 chambered shell ; it occurs in two different types (like 



males and females, though that does not seem to be the 



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