10 
flowers. The intense muscular effort and fatigue had stopped 
digestion. The seeds must have been in the crop at least twelve 
hours, and probably much longer, for no bird could, in a high 
wind, take a perfectly direct course. I have no doubt this fact is 
well known to most of you, that intense exertion, either muscular 
or mental, inhibits digestion and may for a time stop it entirely. 
A quail is by no means the strongest bird on the wing, and, 
compared with many birds, fatigue seems to come on rapidly ; 
but, let it be said for the credit of the quail family, if they possess 
less power for sustained effort, their sense of sympathy seems to 
be more highly developed than in some other birds. Travellers 
tell us that among the quails that are strongest on the wing, and 
which have previously gone the same journey, some have been 
observed at sea, bearing on their backs the tired ones, which have 
thus in a desperate situation found safety. Some very valuable 
observations have been recorded of fatigue in pigeons, especially 
carrier pigeons. Nine pigeons brought from the United States 
were set free in London; only three succeeded in crossing the 
ocean, and returning to their homes. After a very long flight the 
brain and muscles of two fatigued birds were compared with the 
same organs of healthy birds. The contrast was most marked, 
and was at once noticed by the professor and students alike 
working in the laboratory. In the fatigued birds the brain was 
pale, almost bloodless, and so were the muscles. The rectal 
temperature was 43 C., one degree C. above normal. The speed 
of a pigeon is greater than that of a quail, and the former can 
travel longer journeys with less fatigue. That the strength of 
animals increases proportionately as their size decreases is a fact 
well known to old writers. Haller in his treatise on physiology 
compares the strength of a London porter with that of a horse, 
and concludes that the former is proportionately the stronger. 
Plateu notes that the common beetle can drag along a mass 
fourteen times as heavy as its own body; other insects can drag 
as much as forty-two times their own weight. The horse can 
only pull twice or thrice its own weight. This same writer notes 
that of two species of insects belonging to the same family, which 
differ in weight, the smaller and lighter is always proportionately 
the stronger. An ant can carry a burden twenty-three times as 
heavy as itself. In no animal is muscular contraction so rapid, or 
so frequent, as in insects. Lubbock tells us the note of the wings 
in flight of the common bee is La, that is 440 vibrations per 
second. In Bombus terristris the male buzzes in La, whilst the 
female, a larger insect, buzzes an octave higher. 
I have spoken of fatigue overtaking birds whilst travelling. 
Sad to relate, many human beings share a like fate every year. 
Every year thousands of Piedmontese workmen go to France or 
Switzerland, returning at the beginning of winter by the valley of 
oe 
