BEFORE THE DAWN OF ART 281 



gravity, they will lie at the same level in the ooze; 

 and so it may be in some cases. But that this is 

 not all is proved by individuals which make the 

 bulk of the shell of microscopic quartz grains, but 

 interpolate at intervals little gems of garnet, 

 magnetite, and perhaps topaz. 



Speaking of a Foraminifer common on the rocks 

 of the Mixon Beacon, a couple of miles out to sea 

 from the point of Selsey Bill, Mr. Heron-Allen 

 writes : " Among the shells of this species, the 

 majority of which are neatly constructed in the 

 ordinary way, of very small quartz grains, built 

 together with a brilliantly white or deeply ferrugi- 

 nous cement (which gives a very distinctive color- 

 ing to the shells }, frequent specimens are found 

 which have selected and built into their shells rela- 

 tively large fragments of these gem materials, and 

 though even I would shrink from suggesting the in- 

 clusion among the higher qualities of Foraminiferal 

 protoplasm of an ' aesthetic sense,' the selection of 

 these grains of markedly higher specific gravity by a 

 very restricted proportion of the animals of this 

 species seems to me to be exceedingly significant. It 

 affords a parallel to the instances of selection, by dif- 

 ferent species living on the same bottom, and sur- 

 rounded by the same materials, of entirely, different 

 elements, to which Lister has called attention." In 

 contrast to a shell of quartz grains we may mention 

 that of a species of Reophax a fragile many- 

 chambered tube built of infinitesimally small flakes 

 qf mica, joined at their extreme margins by chitinous 



