DEVONIC FISHES OF THE NEW YORK FORMATIONS I 73 



SUMMARY AND CONCLUSIONS 

 The immediate purpose of the foregoing section has been to present a 

 systematic account of the fossil fishes known from a definite area of the 

 American Devonic, with occasional notice of related extralimital forms. 

 Distinguishing characteristics have been set forth with considerable fulness, 

 and the descriptions of species follow the usual order of zoological classifi- 

 cation. Their more general relationships have been pointed out, and the 

 geological horizon is registered in all cases. An accumulation of details, 

 such as is here brought together, is requisite for the identification of species 

 and for an understanding of the material facts concerning them. We must 

 first have an abundance of actual facts of this nature before it is possible to 

 establish broad generalizations ; and to acquire validity, these latter must 

 repose upon the sum total of information now at our disposal in regard to 

 Devonic fishes. Conclusions based upon the fauna of a circumscribed area 

 can not have a wide application or significance unless brought into adjustment 

 with our knowledge of antecedent, contemporary and later faunas, whether 

 from the same geographical province, or from remote quarters of the globe. 

 There are no other means for attaching significance to a truth except 

 by perceiving its relations to other truths. Thus far we have been con- 

 cerned principally in assembling, and to some slight extent in correlating 

 recognizable truths ; in a word, facts of observation have been brought into 

 orderly array. The next step is to examine them in their bearing upon 

 other known facts, to deduce their general significance, and to assign to the 

 results a commensurate worth in surveying the whole field of paleonto- 

 logical inquiry. The ultimate yield of scientific study is the fruition of 

 philosophical ideas. 



To obtain a large perspective of the body of facts at our disposal, it is 

 desirable to marshal them in different ways, and to examine them from 

 different points of view. Their relevancy from a geological standpoint 

 needs consideration, with the object of drawing from them conclusions of 

 geological import. In still larger measure it behooves us to consider 



