178 HABITS oF BIRDS. 
that seems of universal comprehension, and this 1s 
the signal of danger: the instant it is uttered, we 
hear the whole flock, though composed of various 
species, repeat a separate moan, and away they all 
scuttle into the bushes for safety.’’* 
The latter circumstance, however, is contrary to 
all that we have ever observed; for, instead of fly- 
ing or hiding from danger, the alarm-call seems to 
imbolden even the most timid to run every hazard; 
and, accordingly, it is matter of common observa- 
tion, that whenever a hawk makes his appearance, 
the first swallow which descries him sounds the 
tocsin, when not only all the swallows in the vicin- 
ity muster their forces, but many other small birds 
hurry to the spot, and, so far from skulking away 
out of danger, they boldly face their powerful foe, 
attacking him fearlessly with beak and wing, tll 
some individual pays the penalty of his temerity. 
With this exception we can bear testimony to the 
description of Mr. Knapp being minutely correct. 
** Some,” he adds, “ give the maternal hush to their 
young, and mount to inquire into the jeopardy an- 
nounced. The wren, that tells of perils from the 
hedge, soon collects about her all the various in- 
quisitive species within hearing to survey and as- 
certain the object and add their separate fears. 
The swallow, that, shrieking, darts in devious flight 
through the air when a hawk appears, not only calls 
up all the hirundines of the village, but is instantly 
understood by every finch and sparrow, and its 
warning attended to.’’t 
Dr. Darwin, in his usual ingenious but fanciful 
manner, endeavours to show that this language of 
fear and alarm is (like other sounds usually con- 
sidered natural) acquired and conventional like hu- 
manspeech. His facts will amuse the reader, while 
nis inferences must appear quite hypothetical and 
* Journal of a Naturalist p. 268, third edit. { Ibid. 
