THE USE OF LOCAL NAMES IN GEOLOGY 1 67 



them until after they were proposed ? And who can pass 

 judgment on any terms until they are suggested ? Or who 

 can say whether they would be useful or not until they are 

 tried ? 



In this day and age the geological sciences are protected at 

 the start by one great safeguard against the promiscuous intro- 

 duction of new names. There is one test that every new name 

 must stand before it can venture to ask for recognition. This is 

 the test of definition. Every "new name in geology must be 

 properly defined before it can be noticed at all. Its subsequent 

 career depends upon its utility. 



It has been already intimated that the rate with which a 

 science is advancing is measurable by the number of new 

 and useful terms that appear. At present this statement is 

 especially true of some of the geological sciences. To be sure, 

 new terminology does not necessarily indicate new facts, but 

 when new terms receive the favor of those best qualified to 

 pass judgment upon them, of the specialists in the particular 

 department, when also these names stand for new conceptions, 

 the branch of knowledge thus affected is certainly undergoing 

 such radical change that the final outcome must be essentially 

 very different from the old. This rapid change in terminology 

 is at present characteristic of several of the branches of 

 geology. 



In no department has the coining of new names gone on more 

 vigorously than in stratigraphical geology. The reason is to be 

 found partly in the inherent conditions existing in this field, and 

 partly in the complete change of base that this branch of the 

 science has undergone in late years. The fundamental conception 

 of the geological formation, whether large or small, whether 

 a single bed or a great series, is a sharply defined " geological 

 unit," instead of a vaguely bounded "group" of layers. The 

 former is now capable of being clearly demarcated by strictly 

 physical characters, that are the direct outgrowths of the actual 

 conditions giving rise to the formations themselves ; the latter is 

 too often based upon trivial or accidental characters which are 



