REPORT OF THE SECRETARY. , 13 



state of the earth's crust and the appreciation of the phenomena that 

 there take place, of the intimate transformation of rocks, of the 

 mechanical destruction of the layers, of their reconstruction under 

 new forms, allows us to draw an inference by analogy as to the more 

 ancient transformations and the agents which have produced them ; so 

 the study of species and of their actual existing transformations seems 

 likely to enable us to follow up the chain of these transformations to a 

 point more or less close to their origin. The definition of the first di- 

 vergences observable in the permanent varieties, which may be consid- 

 ered as nascent species, in order to ascend afterward to the relation- 

 ship of species separated by the divergences more and more profound, 

 such is, we deem, the point of view under which we should never neglect 

 to study species. 



"Zoology only when considered from this point of view is philo- 

 sophical. It has not its aim in itself; it serves only as a means to sift 

 questions of a higher order. Now, entomology is precisely the one of 

 the branches of zoology in which the study of the filiation of species 

 may become the most fecund in results, either on account of the multi- 

 tude of ramifications of general types and of the multiplicity of forms 

 under which each type appears, or on account of the smallness of the 

 breaks which separate genera and species, or also on account of the 

 immense variety of forms and of the facility with which species seem to 

 become modified in proportion as they spread over the surface of the 

 globe in following diverging ways. Thanks to all these causes, it is not 

 difficult to find examples of every kind of filiation ; not difficult, either, 

 to follow over latitudes certain modifications still recent which allow us 

 to draw an inference by analogy as to other modifications more profound 

 because they are more ancient, and as to others of a degree still more 

 advanced. 



" Unfortunately in our times the greater number of entomologists have 

 deviated too far from this philosophical path. They have turned ento- 

 mology into a sort of amusement, which has for its object the discovery 

 of new species; which loses itself in minutiae, and at the bottom of 

 which there exists no thought. Thanks to this tendency, collecting has 

 ceased to be the means, and has become the object. In becoming an 

 amusement entomology has gradually lost caste j it has fallen into the 

 hands of dawdlers, and thus lost a part of its scientific character. This 

 transformation has led men who aim at reaching an elevated rank in 

 science to be too much inclined to withdraw from the field of entomology. 



"As may be anticipated from what precedes, my intimate purpose in 

 producing this work is to study the American fauna with a view to its 

 origin. But this is a work of time which cannot be completed off-hand. 

 The first thing to be done is to study carefully the species, to arrange 

 them according to a good classification, and to describe, while proceed- 

 ing, their affinities. That is the fundamental preparatory labor. I 

 have not the pretension to overstep those limits in this monograph. 



