The daily morning journal and courier. [volume] (New Haven, Conn.) 1894-1907, 1897-12-07

the humming birds throat, the glitter
ing green of tfogons, and so on, and it
is noteworthy that perhaps all the birds
thus gorgeously appareled lay white
eggs ...,
1t is justly believed. indeed, that in
the beginning all birds produced white,
unspotted, soft-shelled eggs, following
the rule of the reptllian class, from
which birds have no doubt arisen.
How the change toward a hard and
differently shaped shell and the addl-
tion of colors came about we may never
know. 1t is the great obstacle to this
line of investigation that almost no his
torical evidence Is in existence, or is
ever likely to be; and yet In the past is
hidden, no doubt, the key to the pro-
blem Zoology now presents when APP
preached by the evolutionist.
1.-THE first thing which strikes the eye
OF one who beholds large collection Of
egg shells is the varied hues of the
specimens. Hardly a shade known to
the colorist is not exhibited by one or
more, and some of these tints have their
beauty enhanced by the glossy sur
face on which they are displayed, by
| their harmonious blending, or by the
pleasing contrast Of pigments which
form markings as often of the most ir-
| regular shape
That Is a flower from the desert Of
the Encyclopaedia Britannica!
The colors flow from pigment pores in
the uterine dilatation Of the oviduct
where the shell is formed, and partially
accompany that process, all eggs show
S,,,~ at fn,,
the most part laid on after the shell has
been finished, and the streaking and
marbling distinguishing many are due
| to the progress and rotation of these
kinds while the color is still eXuding
upon them. Newlylaid eggs will some
times smear, or the color may be
washed off. Mr.. Hewitson, the pioneer
Of British authorities on Zoology, ascer-
tanned long ago that 'fear, or anything
which may affect the animal functins,
influences the color" of a birds egg, and
says that the eggs Of birds he has cap
tured on their nests during the time
that they were laying, and has kept in
close confinement, have thus been de-
prived Of much of their color. Age
showed itself in a, similar way, size and
color increasing from youth to maturi-
ty, and declining beyond that.
Spectrum analysis shows that all the
many tints of birds eggs, multiplied
and varied by blending, immersion in
the SHE'LL etc, are due to seven pig
ments, each so singular as to merit
name. Their chemical properties close
| ly connect them with hemaglobin, the
coloring matter Of the red corpuscles of
| the blood, and with the bile pigments,
the latter lot furnishing blues and yell
lows, which in mixtures form various
clear greens The ordinary color of
such eggs as are not white Is some tint
of blue or green. varying in one direc-
tion toward olive, and in the other to
"robin's-egg" blue; and the commonest
pigment In markings is reddish brown,
rarely absent In some tint.
Some eggs are Sbeckled or blotched all
over nearly uniformly, but in most the
markings are densest around the larger
end, where they form pretty wreath
the record apparently of a period of rest
and pressure against zone OF pigment
pores The egg passes down the owl
duct large end first (although the oppo-
site progress, like a round wedge, would
seem at first glance more naturaD, be-
cause that is head-foremost for the en-
bryo, following the rule of animal
births.
While the eggs of some birds are re-
markably constant in color and mark
ings, most Of them exhibit considerable
variety and Inconsistency, amounting to
diversity of ground tint as well as of or
namentation. Spotted examples of nor
mally plain eggs, and the opposite, are
| freu11pnt occurrences
These particulars have been given not
only because they were thought to be
interesting in themselves but because
they show how purely matter of or
ganic functions is the painting Of a
birds egg-something over which the
hen has no voluntary control whatever.
Ernest Ingersoll in Harpers Maya
zine.