614 OHIO BIRDS. 
species are witheut wing-bars, while in D. palmarum, so far as known the only ground- 
nesting Dendreeca, the wing-bars are wanting. In this family the presence or absence 
of wing-bars seems to be associated with the presence or absence or more or less perfect 
developement of tail spots (not tail-tips, however, in the sense used above), except in the 
case of Myiodioctes mitratus where wing-bars are wanting but tail spots are well developed. 
It may be further said with regard to the presence of wing-bars that they seem to be 
more perfectly developed in the northern than in the southern birds of a genus. 
I have brought before you many specimens of our Ohio Birds for the purpose of inquir- 
ing into relations which exist between the color cr pattern of coloration and the mean 
annual temperature to which these birds are subjected. In this investigation, I shall 
assume that birds which are only winter visitors with us are subject to the lowest tem- 
perature ; that those which are resident throughout the year with us are next in order 
in this respect, while summer residents may be considered as subjected to the highest 
average temperature, and spring and fall migrants to an average temperature higher 
than that of residents. 
There is a well-known law that when the adult male and female of a species resemble 
each other the young differ from either parent ; and, when the adult male and female 
are unlike, the young resemble the female. I wish now to make a series of comparisons 
showing the relations between young of different species, or the young of one species 
with the adult of another. But first I will call your attention to a few birds for the 
purpose of illustrating the law of resemblance or difference between the young and old 
of the same species. We have here the male and female of one of our most common 
birds, the Robin, Turdus migratorius, and they wil! be seen to resemble each other very 
closely both as to pattern of coloration and color. Their young, however, differ both 
in color and pattern. In the other case, we have the Purple Finch, Carpodacus pur- 
pureus, the male of which is adorned with bright though shaded or blended colors, 
while the female is much plainer, lacks the bright color and is thickly dusky-streaked. 
The sex of the young male could not be determined by the markings or color, asin both 
these the resembiance to the female is almost perfect. In some cases the male and fe- 
male differ in eolor but not in pattern, as here in the case of the Tewhe Bunting (Pipilo 
erythrophthalmus). In this case the young bird differs from either parent. 
There appsar to be among young birds three distinct primary patterns of plumage, 
the spotted, barred, and streaked ; in the developement ef the individual these may re- 
main permanently, and more or less completely, or be transformed into another pattern 
by the blending of two of these, or into definite or indefinite color areas. 
In making the following comparisons between birds of our own State, our point of 
observation, in this city, is favorable, being central and very near the fortieth degree of 
latitude. 
I have here six birds, all of them True Thrushes and all of different species. Five of 
these present on their under parts a more or Jess distinctly spotted pattern while the 
sixth is uniform or nearly so in the region where the others are spotted. You recognize 
this sixth specimen as the Robin, Turdus migratorius, of which I made use in illustrat- 
ing the differences between old and young birds. On comparing the young of the Robin 
with the other five Thrushes, the pattern of coloration is seen to be the same. 
If now we arrange these birds, placing that bird first whose southern breeding limit, 
so far as known, is most northerly, and the others following in the same order we have : 
1, Turdus alicia, 
2, Turdus swainsoni, 
x 
Vinee: 
