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. However, it is perhaps silly to
be minutely particular in dealing with silly statements such as this.
The windpipe then, owing to its position in front of the oesophagus,
is exposed, as we have said, to annoyance from the food. To obviate
this, however, nature has contrived the epiglottis. This part is not
found in all sanguineous animals, but only in such of them as have a
lung; nor in all of these, but only in such as at the same time have
their skin covered with hairs, and not either with scaly plates or
with feathers. In such scaly and feathered animals there is no
epiglottis, but its office is supplied by the larynx, which closes and
opens, just as in the other case the epiglottis falls down and rises
up; rising up during the ingress or egress of breath, and falling down
during the ingestion of food, so as to prevent any particle from
slipping into the windpipe. Should there be the slightest want of
accuracy in this movement, or should an inspiration be made during the
ingestion of food, choking and coughing ensue, as already has been
noticed. So admirably contrived, however, is the movement both of
the epiglottis and of the tongue, that, while the food is being ground
to a pulp in the mouth, the tongue very rarely gets caught between the
teeth; and, while the food is passing over the epiglottis seldom
does a particle of it slip into the windpipe.
The animals which have been mentioned as having no epiglottis owe
this deficiency to the dryness of their flesh and to the hardness of
their skin
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