THE JACKDAW AND THE STARLING, ETC. 135 
perform any required evolution exactly in unison with 
the movements of that leader. Even this theory, 
however, will not account for the sudden dispersion 
into smaller flocks, each with its temporary guide, 
and their equally sudden reunion into a common 
body. Yet, what other explanation is possible? No 
sound can be uttered, and, even were some such 
signal to be given, it could not travel to the ex- 
tremities of the flock with sufficient speed to account 
for the perfect unanimity of every movement. 
Science and conjecture, indeed, are equally at fault 
when attempting to explain the mystery, and we can 
only relegate it—at any rate for the present—to the 
ever-increasing list of natural phenomena the causes 
_ of which are still concealed from our understanding. 
Like the jackdaw, the starling always selects a 
sheltered spot for its nest, and generally chooses some 
such situation as a tower or steeple, an old ruin, a 
water-pipe, or a hole in a decaying tree. Every now 
and again, however, a nest is found in an inverted 
flower-pot, a rabbit-burrow, or some other wholly un- 
expected locality. 
Nest, perhaps, is hardly the mght word by which 
to describe the starling’s domicile, for the bird does 
little more than pile together a quantity of straw, hay, 
roots, and feathers, its architectural talents seeming 
to be quite inadequate for the task of building, pro- 
perly so called. The bird has little idea of conceal- 
ment, frequently allowing a streamer of straw or hay 
to point out the position of the nest to the most 
careless observer, while, as if such a token were in- 
