1910] Grinnell—Savannah Sparrow of the Great Basin. 313 
refute the notion entertained by certain ornithologists that 
subsequent molts lead normally into conditions of coloration 
more emphatically specific. Further, the fact that old birds are 
no more extreme in their differential characters than juvenals 
may be interpreted as showing that there is no ‘‘direct action”’ 
of the environment upon the individual, at least as affecting its 
coloration, during the portion of its life-time beyond the period 
of juvenal feather growth. Since the results of experimental 
biology indicate that the earliest, prenatal, stages are impres- 
sionable to a great degree by external influences (as of light, 
temperature, and pressure), the whole problem of the germinal 
versus the somatic nature of such characters as those here consid- 
ered demands further investigation. 
CHARACTERS.—Resembles Passerculus sandwichensis alaudi- 
nus Bonaparte, but much paler throughout in all plumages: 
white replacing buff, black streaks thus more conspicuously con- 
trasted, there being a minimum amount of hazel marginings; 
size slightly less. From P. s. savanna (Wilson), the new form 
differs in coloration in the same ways as above but in greater 
degree; the bill is proportionally much smaller, though the wing 
leneth is nearly the same. From the other described forms of 
the Savannah sparrow, nevadensis is still more divergent. 
DESCRIPTIONS. 
Juvenal plumage. (based on type of P. s. 
nevadensis) : throat, post-pectoral region and crissum pure 
white; flanks narrowly black-streaked on a white ground; pec- 
toral region sharply black-streaked on a very pale cream-buft 
ground; sides of head and neck flecked with black on a pale 
eream-buff ground; superciliary and median crown stripes 
whitish, the former minutely flecked with blackish; lateral crown 
stripes, to hind neck, broadly black streaked on a ground of 
pale clay color; feathers of dorsum with broad coal-black central 
areas margined with whitish; tippings of wing coverts and edg- 
ings of inner wing quills broadly whitish; edgings of wings 
otherwise, scapulars and tail, clay color. 
A specimen of P. s. alaudinus (no. 3622, Grinnell coll.; Cape 
Blossom, Kotzebue Sound, Alaska; July 26, 1898) in parallel 
plumage is conspicuously browner than the above: whole lower 
surface pervaded with buffy, and pectoral region, sides of head 
