PARENTAL AFFECTION IN THE SWAN. 253 
the sternum for the reception of the trachea, which is admirably 
described by Mr. Yarrell as descending the passage between the two 
branches of the forked bone called the merrythought to a level with 
the keel of the breast-bone, which is double, and receives the tube of 
the trachea between its two sides, which here turns upon itself after 
traversing the whole length of the keel, and passes upwards and 
forwards, and again backwards, till it ends in the vertical bone where 
the two bronchial tubes go off, one to each lobe of the lungs. This 
is the apparatus through which the cry is produced, which is variously 
described as a whistle, a whoop, or a song, according to the fancy of 
the writer. They fly at a great height when on a migratory journey, 
and in a wedge-like figure, uttering this note as they proceed, and 
when heard at a distance it is not unmusical. Mr. McGillivray listened 
to a flock of wild swans coming in from the Atlantic after a gale; 
their clear, loud, and trumpet-like cries delighted him as they sped 
their way in lengthened files ; but they were too far off for him to 
decide whether or not they were of this species. 
The female lays from six to eight eggs, of a greenish white, and 
the incubation lasts about six weeks. ‘The cygnets are at first covered 
with a grey down, and do not put on their adult plumage until the 
third year. Swans care but little for concealing their broods, as they 
feel confident of their power to protect them against every enemy. 
They will fight even with the Eagle itself, harassing it with beak and 
wings, until the marauder is glad to make a more or less honourable 
retreat. 
In the protection of their young they display extraordinary courage. 
On one occasion a female swan was sitting on the bank of a river, 
when she perceived a fox swimming towards her from the opposite 
bank. Thinking that she would be better able to defend herself in her 
natural element, she took to the water and went to meet the enemy 
which was threatening her brood. She soon reached him, and, spring- 
ing upon him with much fury, gave him such a violent blow with her 
wing that the fox was disabled, and consequently drowned. 
The male swan is equally attentive with the female to their brood, 
and watches them with a rare devotion. He carries them about on 
his back, takes them under his wings to warm them, and never 
abandons them while they are still young. It isa beautiful sight to 
see him gliding over the water at the head of his young flock, 
looking forward with an inquisitive eye, and quite prepared to sweep 
away any opposing obstacle; whilst the mother keeps some distance 
behind, ready to protect the rear. How much, too, are they te 
be admired as they sail majestically along over the surface of some 
