5018 THE ZooLocist—Aveust, 1876. 
colours of the female bird to the tints of surrounding objects, during the 
trying period of incubation, and the establishment of certain resemblances 
to familiar external objects, are two of the ways in which it manifests 
itself.” 
In old times, before the forests had been thinned by the wood- 
man’s axe, the Baltimore oriole found in the dense foliage of the 
trees in which it placed its nest sufficient protection from the 
burning sun. But now that this shelter has been generally 
encroached upon, the bird has learned to weave an outer covering 
and roof for its nest: “They interweave and fabricate a sort of 
coarse cloth into the form intended, towards the bottom of which 
they place the real nest, made chiefly of lint, wiry grass, horse- and 
cow-hair.” The peewit flycatcher (Sayornis fuscus) has supplied 
instances of deviation from the ordinary and characteristic form of 
nest built by this species; several nests found in a barn were more 
loosely constructed than others placed in exposed situations, the 
birds plainly perceiving the advantage of adapting their plan to 
the circumstances of the site. A correspondent of Dr. Coues, 
Mr. Gentry, actually succeeded in inducing a pair of cedar-birds 
(Ampelis Cedrorum) to modify their nests by supplying them with 
unaccustomed building materials :— 
“While watching a pair of Ampelis Cedrorum, engaged in the building 
of a nest on a branch of an apple-tree, it occurred to me that, by supplying 
them with materials, I might secure a nest neater and more compact than 
those usually made. The birds entered into the project with readiness, and 
carried away every piece of coloured string and cotton fabric with which 
I supplied them. After I had ceased to furnish the materials they would 
fly repeatedly to the branch where the articles were deposited, as if im- 
ploring my services. The result was a nest firmer, more symmetrical, and 
more elegant in proportions than any I had ever observed. If instinct had 
been the controlling principle in this case, the birds would not have given 
my labours so much attention; but admitting that they had been actuated 
by reasoning faculties in their selection, the whole thing is perfectly 
plausible. Instinct is always the same thing; it never advances, never 
retrogrades; but reason tends to improvement, when it can serve a good 
purpose.” 
We may add, in confirmation of these last words of Mr. Gentry, 
the case of a wood-lark’s nest which once came under our observa- 
tion. ‘This nest was discovered upon the ground in a rough field 
full of ferns, thistles and other weeds, and had eggs init. Passing 
