PERSOXA L O BSER I 'A TION. 3 3 



If we find an insect, we may presently refer it to the 

 Lspidoptera, and then to the butterflies ; but when it 

 comes to distinguishing between the various Vanessas, 

 with their curious punctuation marks, the matter 

 grows more serious, and we are compelled to obtain a 

 book more restricted in scope than a zoology, and, in- 

 deed, than most entomologists. 



As a result of this, it becomes necessary for him 

 that would accurately study any department of nature 

 to limit himself early to a small field. One will 

 choose, for instance, dragon-flies, and by devoting 

 years to them will become a specialist and an authority 

 in that department. It is the tendency of the times 

 to produce specialists. 



Many persons, however, are not willing to restrict 

 themselves to so narrow a field of study. They pre- 

 fer to range freely over mountain and along stream ; 

 and having acquired the power to analyze a flower or 

 determine a mineral, they leave the one to nod and 

 smile on its dewy stem in undissected beauty, and the 

 other to sparkle in the sunlight, instead of crackling 

 in the reducing flame of a compound blowpipe. Yet 

 we must have strict scientists, and we honor the men 

 who for the sake of expanding the world's knowledge 

 are willing to confine their own researches to a narrow 

 field. 



For those, then, who are old enough to pursue a 

 systematic course, we have briefly outlined a plan 

 which may be followed in any department of natural 

 science. It consists in first obtaining a general view 

 of the whole field, and then in learning its successive 

 subdivisions, until analysis is complete. 



The rest of you, and especially you, my little folk 

 of ten years old and under, may, for the present, leave 

 the big books unopened, and the Latin names un- 

 learned. Watch the minnows dart about in the crystal 



