The Three Secretaries 177 



ture, and it is very likely to be either under- or over-valued by 

 those who are not familiar with the study of living organisms. 

 Classification, description, and naming of the different forms 

 are the essential foundations of scientific biology, for until this 

 has been done identification of particular forms is either diffi- 

 cult or impossible, cooperative work on the part of scattered 

 students is greatly restricted, and broad generalizations can 

 only be put in the form of theories and conjectures. Such 

 work as was done by Professor Baird in this direction gives a 

 starting point to many observers and investigators in different 

 localities, stimulates farther inquiry, and, when done on the 

 extensive scale on which he did it, based on the examination 

 and comparison of a large number of specimens from widely 

 different localities, exercises a powerful influence for years to 

 come on lines of exploration, collection, and critical research. 

 To those who have never tried it, it may seem an easy matter 

 to sort out specimens of different kinds when a large number 

 are brought together, or to prepare descriptions sufficient to 

 enable another man to identify his specimen ; but in reality 

 it requires not only much experience and careful study, but a 

 certain aptitude, power of grasping salient points, and of put- 

 ting aside unessentials such as are rarely possessed by any 

 man." 



As an example of Professor Baird's ability in generaliza- 

 tion, Doctor Billings cites his paper on the distribution and 

 migrations of North American birds. In this he maps out 

 the country into regions corresponding to the distribution of 

 different kinds of birds ; discusses the relations of these re- 

 gions to surface topography, altitude, temperature, mountain 

 chains, etc. ; points out that there are certain correspondences 

 in the distribution of reptiles and fishes, and draws the con- 

 clusion that North American birds of wide distribution in lati- 

 tude, whether migrants or residents, will be found to be larger 



