THE IMPENETRABLE SEA 



Protozoa to invertebrates and upwards to such weird 

 creatures as squids, and upwards again from them, 

 through fishes of many kinds, to mammals hke ourselves. 

 Everywhere, through countless myriads of life-forms are 

 these waving "hairs" which are organs which baffle the 

 most detailed examination. 



The cilia tracts — hairy surfaces — around the throats of 

 such protozoic creatures as Paramecium and Vorticella are 

 specialized filter-feeding mechanisms — so are the ciliated 

 rings around the mouths of rotifers, which get their name 

 from the curious "spinning" eflfect caused by the rapid 

 movement of the whip-like hairs as they flash rapidly 

 around each pulsating ring. 



Oysters and mussels use these microscopic whips, for 

 their gills are covered with a ciliated epithelium or outer 

 layer, over which a constant stream of mucus flows, 

 catching particles of food and conveying them to the 

 creature's open gullet. 



Few people realize, when they clear their throats of 

 phlegm, that they are only able to do so (saving their 

 lungs from accumulations of mucus) because their 

 throats are lined with cilia similar to those which carry 

 particles of food into the gullets of oysters. We call 

 these microscopic "hairs" which line our throats cilia, 

 but, like all cilia of the types we have been considering, 

 our "throat-hairs" have all the characteristics of flagella. 

 The oyster's "whips" wave the food particles into its 

 gullet ; the sponge's waving flagella beckon microscopic 

 planktonic sea creatures into its canals ; and the whips 

 which line the throat of a man are continually in action 

 passing particles of injurious dust upwards until they 

 reach his nose and mouth, mixed with the mucus without 

 which the flagella cannot act (for they always operate in 

 liquids) and so being carried out of the human organism, 

 even as food particles are carried into the organisms of 

 sponges, molluscs and other creatures. 



So in the process of conception, ciliated tracts, also 



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