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e at the same time generally raised； as by this movement respiration is rendered easier。 With one of my infants； when seventy…seven days old； the inspirations were so rapid and strong that they approached in character to sobbing； when 138 days old I first noticed distinct sobbing； which subsequently followed every bad crying…fit。 The respiratory movements are partly voluntary and partly involuntary； and I apprehend that sobbing is at least in part due to children having some power to command after early infancy their vocal organs and to stop their screams； but from having less power over their respiratory muscles； these continue for a time to act in an involuntary or spasmodic manner； after having been brought into violent action。 Sobbing seems to be peculiar to the human species； for the keepers in the Zoological Gardens assure me that they have never heard a sob from any kind of monkey； though monkeys often scream loudly whilst being chased and caught； and then pant for a long time。 We thus see that there is a close analogy between sobbing and the free shedding of tears； for with children； sobbing does not commence during early infancy； but afterwards comes on rather suddenly and then follows every bad crying…fit； until the habit is checked with advancing years。
＇11＇ ‘De la Physionomie；' 1865； p。 126。
_On the cause of the contraction of the muscles round the eyes during screaming_。We have seen that infants and young children； whilst screaming； invariably close their eyes firmly； by the contraction of the surrounding muscles； so that the skin becomes wrinkled all around。 With older children； and even with adults； whenever there is violent and unrestrained crying； a tendency to the contraction of these same muscles may be observed； though this is often checked in order not to interfere with vision。
Sir C。 Bell explains＇12＇ this action in the following manner：〃During every violent act of expiration； whether in hearty laughter； weeping； coughing； or sneezing； the eyeball is firmly compressed by the fibres of the orbicularis； and this is a provision for supporting and defending the vascular system of the interior of the eye from a retrograde impulse communicated to the blood in the veins at that time。 When we contract the chest and expel the air； there is a retardation of the blood in the veins of the neck and head； and in the more powerful acts of expulsion； the blood not only distends the vessels； but is even regurgitated into the minute branches。 Were the eye not properly compressed at that time； and a resistance given to the shock； irreparable injury might be inflicted on the delicate textures of the interior of the eye。〃 He further adds； 〃If we separate the eyelids of a child to examine the eye； while it cries and struggles with passion； by taking off the natural support to the vascular system of the eye； and means of guarding it against the rush of blood then occurring； the conjunctiva becomes suddenly filled with blood； and the eyelids everted。〃
＇12＇ ‘The Anatomy of Expression；' 1844； p。 106。 See also his paper in the ‘Philosophical Transactions；' 1822； p。 284； ibid。 1823； pp。 166 and 289。 Also ‘The Nervous System of the Human Body；' 3rd edit。 1836； p。 175。
Not only are the muscles round the eyes strongly contracted； as Sir C。 Bell states and as I have often observed； during screaming； loud laughter； coughing； and sneezing； but during several other analogous actions。 A man contracts these muscles when he violently blows his nose。 I asked one of my boys to shout as loudly as he possibly could； and as soon as he began； he firmly contracted his orbicular muscles； I observed this repeatedly； and on asking him why he had every time so firmly closed his eyes； I found that he was quite unaware of the fact： he had acted instinctively or unconsciously。
It is not necessary； in order to lead to the contraction of these muscles； that air should actually be expelled from the chest； it suffices that the muscles of the chest and abdomen should contract with great force； whilst by the closure of the glottis no air escapes。 In violent vomiting or retching the diaphragm is made to descend by the chest being filled with air； it is then held in this position by the closure of the glottis； 〃as well as by the contraction of its own fibres。〃＇13＇ The abdominal muscles now contract strongly upon the stomach； its proper muscles likewise contracting； and the contents are thus ejected。 During each effort of vomiting 〃the head becomes greatly congested； so that the features are red and swollen； and the large veins of the face and temples visibly dilated。〃 At the same time； as I know from observation； the muscles round the eyes are strongly contracted。 This is likewise the case when the abdominal muscles act downwards with unusual force in expelling the contents of the intestinal canal。
＇13＇ See Dr。 Brinton's account of the act of vomiting； in Todd's Cyclop。 of Anatomy and Physiology； 1859； vol。 v。 Supplement； p。 318。
The greatest exertion of the muscles of the body； if those of the chest are not brought into strong action in expelling or compressing the air within the lungs； does not lead to the contraction of the muscles round the eyes。 I have observed my sons using great force in gymnastic exercises； as in repeatedly raising their suspended bodies by their arms alone； and in lifting heavy weights from the ground； but there was hardly any trace of contraction in the muscles round the eyes。
As the contraction of these muscles for the protection of the eyes during violent expiration is indirectly； as we shall hereafter see； a fundamental element in several of our most important expressions； I was extremely anxious to ascertain how far Sir C。 Bell's view could be substantiated。 Professor Donders； of Utrecht；＇14＇ well known as one of the highest authorities in Europe on vision and on the structure of the eye； has most kindly undertaken for me this investigation with the aid of the many ingenious mechanisms of modern science； and has published the results。＇15＇ He shows that during violent expiration the external； the intra…ocular； and the retro…ocular vessels of the eye are all affected in two ways； namely by the increased pressure of the blood in the arteries； and by the return of the blood in the veins being impeded。 It is； therefore； certain that both the arteries and the veins of the eye are more or less distended during violent expiration。 The evidence in detail may be found in Professor Donders' valuable memoir。 We see the effects on the veins of the head； in their prominence； and in the purple colour of the face of a man who coughs violently from being half choked。 I may mention； on the same authority； that the whole eye certainly advances a little during each violent expiration。 This is due to the dilatation of the retro…ocular vessels； and might have been expected from the intimate connection of the eye and brain； the brain being known to rise and fall with each respiration； when a portion of the skull has been removed； and as may be seen along the unclosed sutures of infants' heads。 This also； I presume； is the reason that the eyes of a strangled man appear as if they were starting from their sockets。