XXIV THE STORY OF THE BIRDS. 
Islands thronged and special routes often adhered to. Instinct 
of direction discussed. Leadership of old ones not always present 
to guide young. Birds often get lost. Curious instances of hunt- 
ers “crossings” and “ fly lines.” 
For Study.—Keep a record of coming and going of migrants, 
as noted from window or walk. Get a correspondent north and 
south of you to warn you to “look out.” Learn the migrating 
haunts of various birds in your region, such as certain bushy 
-swales, wood borders, ete. Keep your ears open at night (when 
out) for a migrant’s call. 
Cuaprer XXVIII.—A bird’s ideas of geography, climatology, 
direction, ete., oft inherited from its ancestors, but much comes 
by experience. The distribution of the birds hints much of 
geology. Instance our great plains and the meeting of Hudson’s 
Bay and the Gulf of Mexico formerly. 
Birds seem to know their proper nest, number of eggs, or 
clutch. Instances of vireos appearing to count. Peculiarity that 
the sight of the proper nest number should suppress the forma- 
tion of other eggs in oviduct. Laying not always controllable. 
Effects of weather, fright, etc., on this. Migrant sea bird’s exact 
estimate of time. 
For Study.—Watch for cowbird’s egg and nests about you. 
Destroy them. Take an egg away each day from some laying 
bird and note if she will lay more than her usual number to re- 
place the loss. After one or two eggs are laid fill out her clutch 
with sparrow eggs, and note if she ceases to lay. 
CHAPTER XXIX.—Losses have often been large gains to birds. 
Instances noted in feet, leg, wing, teeth, intestines, carotids, pri- 
maries, palate, ete. Habits also lost down to a vestige, which 
hints former relationship. Instances of ousels, grebes, hoactzins, 
gallinules, rails, geese, ete. Also in nests and in hoarding of 
bright things by crow forms. 
For Study.—Note in a book any peculiar habits of a bird. 
Think if this occurs in any other akin to it. Are the crow of 
cock and croak of pigeon similar—they are kindred groups. 
Note that the brooding domestic pigeon strikes at your hand 
with her wing, and recall that many pigeons have wing spurs, 
Is the rooster’s strut with one wing a vestige or a rudiment of the 
turkey’s and peafowl’s and other pheasants’ perfection of the art ? 
