A BIRD'S BIOGRAPHY. 73 



than in central Illinois or at Washington, D. C, and a 

 week earlier than at Boston. In the fall these conditions 

 are reversed. 



A Bird's Biography. — As a further guide to your 

 observation a list of the principal details which enter into 

 1 bird's life -history is appended : 



1. Description (of size, form, color, and markings). 



2. Haunts (upland, lowland, lakes, rivers, woods, fields, etc.). 



3. Movements (slow or active, hops, walks, creeps, swims, tail 



wagged, etc.). 



4. Appearance (alert, pensive, crest erect, tail drooped, etc.). 



5. Disposition (social, solitary, wary, unsuspicious, etc.). 



6. Flight (slow, rapid, direct, undulating, soaring, sailing, 



flapping, etc.). 



7. Song (pleasing, unattractive, continuous, short, loud, 



low, sung from the ground, from a perch, in 

 the air, etc. ; season of song). 



8. Call-notes (of surprise, alarm, protest, warning, signaling, 



etc.). 



9. Season (spring, fall, summer, winter, with times of ar- 



rival and departure, and variations in num- 

 bers). 



10. Food (berries, insects, seeds, etc. ; how secured). 



11. Mating (habits during courrship). 



12. Nesting (choice of site, material, construction, eggs, incu- 



bation). 



13. The Young (food and care of, time in the nest, notes, actions 



flight). 



From observations of this kind, consisting of a simple 

 statement of facts, you may philosophize according to 

 your nature on the relation between habit and structure, 

 colors and haunts, and intelligent adaptation to new con- 

 ditions. Beware, however, lest you be led to draw faulty 

 conclusions from insufficient observation. Do not make 

 the individual stand for its species, or the species for its 

 family, and remember that one is warranted in theorizing 

 only when the facts in the case are facts indeed. 



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