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Field Columbian Museum — Geology, Vol. i. 



originally regarded by Merrill, calcite. The exact stages of the proc- 

 ess by which vermiform stalactites of calcite would be produced 

 seem to me, therefore, less evident than are those by which such 

 stalactites of aragonite are formed. Yet, until we have better knowl- 

 edge it may be a reasonable hypothesis to suppose that the same 



Fig. i— Deposits produced by capillary attraction, on a stalactite, a glass rod and a glass tube. 



conditions which produce such forms in aragonite (supposing Senft 

 to have correctly judged those conditions) viz.: deposition from 

 dilute solutions in sheltered situations, may be regarded as those 

 which would produce similar forms of calcite. Why, however, ara- 

 gonite should be produced in one case and calcite in the other, I can- 



