adds, we not unfrequently see the hand involuntarily laid upon the
eyelids, as if the better to support and defend the eyeball.
Nevertheless much evidence cannot at present be advanced to prove that
the eye actually suffers injury from the want of support during violent
expiration; but there is some. It is a fact that forcible expiratory
efforts in violent coughing or vomiting, and especially in sneezing,
sometimes give rise to ruptures of the little (external) vessels of
the eye.[617] With respect to the internal vessels, Dr. Gunning has
lately recorded a case of exophthalmos in consequence of
whooping-cough, which in his opinion depended on the rupture of the
deeper vessels; and another analogous case has been recorded. But a
mere sense of discomfort would probably suffice to lead to the
associated habit of protecting the eyeball by the contraction of the
surrounding muscles. Even the expectation or chance of injury would
probably be sufficient, in the same manner as an object moving too near
the eye induces involuntary winking of the eyelids. We may, therefore,
safely conclude from Sir C. Bell s observations, and more especially
from the more careful investigations by Professor Donders, that the
firm closure of the eyelids during the screaming of children is an
action full of meaning and of real service.
We have already seen that the contraction of the orbicular muscles
leads to the drawing up of the upper lip, and consequently, if the
mouth is kept widely open, to the drawing down of the corners by the
contraction of the depressor muscles. The formation of the naso-labial
fold on the cheeks likewise follows from the drawing up of the upper
lip. Thus all the chief expressive movements of the face during crying
apparently result from the contraction of the muscles round the eyes.
We shall also find that the shedding of tears depends on, or at least
stands in some connection with, the contraction of these same muscles.
In some of the foregoing cases, especially in those of sneezing and
coughing, it is possible that the contraction of the orbicular muscles
may serve in addition to protect the eyes from too severe a jar or
vibration. I think so, because dogs and cats, in crunching hard bones,
always close their eyelids, and at least sometimes in sneezing; though
dogs do not do so whilst barking loudly. Mr. Sutton carefully observed
for me a young orang and chimpanzee, and he found that both always
closed their eyes in sneezing and coughing, but not whilst screaming
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