Usually the glass models are made with constant reference to the actual animal under the micro- 
scope, but in the case of this rare specimen of radiolarian very carefully made drawings, plates and 
diagrams only were available. A complicated model sometimes takes two or three months to construct 
Model of another radiolarian, highly magnified. When these minute organisms die their skeletons 
collect on the sea bottom forming a siliceous ooze. The island of Barbados, an elevation of the sea 
bottom, consists very largely of this radiolarian ooze and Barbados earth is used by jewellers for grinding 
and polishing 
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