52 ANIMAL ECOLOGY 



An accurately determined series of specimens, 

 conveniently arranged, will be an important aid 

 in one's studies. Two forms of arrangement of 

 such determined series are very helpful ; one being 

 synoptic or systematically arranged, and the other 

 ecologically, by associations or by a topical arrange- 

 ment in harmony with the subjects being investi- 

 gated. With the use of such series and proper 

 caution, aided by the best keys in the literature, 

 one may hope to make many of his own determina- 

 tions and thus economize his time. 



There are many ways to secure the initial series 

 of determined specimens, and some of these are 

 the following : Our governmental departments, both 

 national and state, and many of our large museums, 

 universities, and academies, have numerous experts 

 who are quite willing and even eager to aid earnest 

 students who wish to have specimens determined. 

 Then, in addition, there are many expert amateurs 

 who are equally liberal, so that when all the sources 

 of aid are considered, the list becomes a surprisingly 

 long one. This is the fact that should be called 

 to mind when considering large numbers of species. 

 A student therefore does not need to work alone, 

 but may have the cooperation of a large number of 

 able and willing collaborators. Naturally we turn 

 for aid to our United States National Museum as 

 one of the first sources of assistance, to the Smith- 

 sonian Institution, and to the various scientific 

 departments of the U. S. Department of Agriculture, 

 particularly to the Bureaus of Plant Industry, 



