A CONTRIBUTION TO THE OOLITE PROBLEM 793 



calcareous bodies on the shore were dissolved in acid, they all yielded 

 dead and shriveled fission algae. Rothpletz, therefore, concluded 

 that the oolites of Great Salt Lake are the product of lime-secreting 

 fission algae, and that their formation is proceeding day by day. 



Furthermore, a study of the recent and near-recent oolites of 

 the Red Sea showed these also to contain minute grains of organic 

 material suggesting fission algae. But these differ from the Great 

 Salt Lake oolites in that their nuclei always consist of sand grains 

 and in that their concentric structure is less well developed. They 

 also possess small vermiform canals filled with calcite, which are 

 interpreted as imprisoned algae of another type. 



Rothpletz also remarks that certain elongated corpuscles pos- 

 sessing oolitic structures, which he interprets as organic, occurs in the 

 Lias limestone of the Vilser Alps, and concludes as follows: "Accord- 

 ing to the present stage of my researches, I am inclined to believe 

 that at least the majority of the marine calcareous oolites with 

 regular zonal and radial structure are of plant origin; the product of 

 microscopically small algae of very low rank, capable of secreting 

 lime." 



In spite of these discoveries by Wethered and Rothpletz, later 

 students of the oolite problem have tended to drift back to the 

 inorganic theory and to regard the association of oolites with algae 

 as accidental. Thus Linck 1 has shown by experiment that oolites 

 similar to natural ones may be produced artificially by the action 

 of sodium carbonate and ammonium carbonate on the calcium sul- 

 phate of sea-water. He points out that these carbonates are formed 

 by decomposition of animal and plant tissues in the sea, and favors 

 the view that oolites have been formed in this way. That natural 

 oolites can be formed chemically is demonstrated by Vaughan, 2 

 who points out that oolitic structure is now being developed in the 

 calcareous muds precipitated through the agency of bacteria off the 

 coasts of Florida and the Bahamas. 



In a recent review of the whole question of oolite formation, 

 T. C. Brown 3 has endeavored to substantiate Linck's conclusions 



1 Neues Jahrb., Beil. Bd. 16 (1903), pp. 495-513. 



2 Jour. Washington Acad. Sci., Ill (i9 T 3)> 3° 2_ 4- 

 s Bull. Geol. Soc. America, XXV (1914), 745-So. 



