animals that have teeth in both jaws ruminate; as, for instance, the
Pontic mice, and the fish which from the habit is by some called
'the Ruminant', (as well as other fish).

    Long-limbed animals have loose faeces, and broad-chested animals
vomit with comparative facility, and these remarks are, in a general
way, applicable to quadrupeds, birds, and men.

                                 49B

    A considerable number of birds change according to season the
colour of their plumage and their note; as, for instance, the owsel
becomes yellow instead of black, and its note gets altered, for in
summer it has a musical note and in winter a discordant chatter. The
thrush also changes its colour; about the throat it is marked in
winter with speckles like a starling, in summer distinctly spotted:
however, it never alters its note. The nightingale, when the hills are
taking on verdure, sings continually for fifteen days and fifteen
nights; afterwards it sings, but not continuously. As summer
advances it has a different song, not so varied as before, nor so
deep, nor so intricately modulated, but simple; it also changes its
colour, and in Italy about this season it goes by a different name. It
goes into hiding, and is consequently visible only for a brief period.

 The erithacus (or redbreast) and the so-called redstart change into
one another; the former is a winter bird, the latter a summer one, and
the difference between them is practically limited to the coloration
of their plumage. In the same way with the beccafico and the blackcap;
these change into one another. The beccafico appears about autumn, and
the blackcap as soon as autumn has ended. These birds, also, differ
from one another only in colour and note; that these birds, two in
name, are one in reality is proved by the fact that at the period when
the change is in progress each one has been seen with the change as
yet incomplete. It is not so very strange that in these cases there is
a change in note and in plumage, for even the ring-dove ceases to
coo in winter, and recommences cooing when spring comes in; in winter,
however, when fine weather has succeeded to very stormy weather,
this bird has been known to give its cooing note, to the
astonishment of such as were acquainted with its usual winter silence.
As a general rule, birds sing most loudly and most diversely in the
pairing season. The cuckoo changes its colour, and its note is not
clearly heard for a short time previous to its departure. It departs
about the rising of the Dog-star, and it reappears from springtime
to the rising of the Dog-star. At the rise of this star the bird
called by some oenanthe disappears, and reappears when it is
setting: thus keeping clear at one time of extreme cold, and at
another time of extreme heat. The hoopoe also changes its colour and
appearance, as Aeschylus has represented in the following lines:-

          The Hoopoe, witness to his own distress,

          Is clad by Zeus in variable dress:-

          Now a gay mountain-bird, with knightly crest,

          Now in the white hawk's silver plumage drest,

          For, timely changing, on the hawk's white wing

          He greets the apparition of the Spring.

          Thus twofold form and colour are conferred,

          In youth and age, upon the selfsame bird.

          The spangled raiment marks his youthful days,

          The argent his maturity displays;

          And when the fields are yellow with ripe corn

          Again his particoloured plumes are worn.

          But evermore, in sullen discontent,

          He seeks the lonely hills, in self-sought banishment.

    Of birds, some take a dust-bath by rolling in dust, some take
a water-bath, and some take neither the one bath nor the other.
Birds that do not fly but keep on the ground take the dust-bath, as
for instance the hen, the partridge, the francolin, the crested
lark, the pheasant; some of the straight-taloned birds, and such as
live on the banks of a river, in marshes, or by the sea, take a
water-bath; some birds take both the dust-bath and the waterbath, as
for instance the pigeon and the sparrow; of the crooked-taloned
birds the greater part take neither the one bath nor the other. So
much for the ways of the above-mentioned, but some birds have a
peculiar habit of making a noise at their hinder quarters, as, for
instance, the turtle-dove; and they make a violent movement of their
tails at the same time that they produce this peculiar sound.

                                -THE END-
.