124 E. HERON- ALLEN AND A. EARLAND ON SOME FORAMINIFERA 



/ 



or at any rate that the separate particles must have become 

 agglutinated during their passage through the alimentary canals 

 of the worms. Annelid remains are of fairly frequent occurrence 

 in the "Huxley" dredgings from the Southern Area, but not 

 noticeably so. 



3. It is a matter of common knowledge that fresh mud or 

 clay, if dried, breaks down readily in water ; but that, if it is 

 worked or "puddled" before being dried, it becomes plastic, and 

 then resists disintegration. It is possible that wave or current 

 action might thus serve to cover the surface of sand-grains and 

 foraminifera with a coating of mud in a plastic or colloidal 

 condition, and on the whole we are inclined to favour this 

 explanation, so far as the viscosity of the " Huxley" deposits is 

 concerned. 



The whole question, however, though interesting from the 

 point of view of the chemist and physicist, lies rather outside 

 the province of the zoologist, although it seems evident that the 

 phenomenon might be of great importance from the geological 

 point of view, as such viscosity would favour the preservation of 

 the encrusted microzoa. 



A very noticeable feature in the " Huxley " dredgings is the 

 roundness of the sand-grains as compared with those of "Goldseeker" 

 dredgings from similar deposits. This is conclusive evidence that 

 the grains have travelled a great distance, or have been sub- 

 jected to tidal action within restricted geographical limits for a 

 prolonged period in comparatively shallow water. The phe- 

 nomenon has been observed in connexion with the Goodwin 

 Sands. The scour of the tides and currents round the Dogger 

 and Great Fisher Banks is doubtless the cause of the rotundity 

 of the " Huxley " sands, the individual grains of which are often 

 as smooth and polished as the Aeolian sands of the desert 

 (PI. 11, fig. 3).* 



* Laboratory experiments have proved that a quartz grain -$ in. in 

 diameter requires an amount of abrasion equal to that acquired in 

 travelling- a distance of 3,000 miles in water before it becomes rounded to 

 the form of a miniature pebble. (Daubree, Geologw Experimentale, Paris, 



