156 EXPRESSION OF SUFFERING: CHAP. VI. them that nothing would relieve them so much as pro- longed and copious crying. The screaming of infants consists of prolonged ex- pirations, with short and rapid, almost spasmodic In- spirations, followed at a somewhat more advanced age hy sobbing. According to Gratiolet,11 the glottis Is chiefly affected during the act of sobbing. This sound is heard " at the moment when the inspiration conquers the resistance of the glottis, and the air rushes into the chest/' But the whole act of respiration is likewise spasmodic and violent. The shoulders are at the same time'generally raised, as by this movement respiration is rendered easier. With one of my infants, when sev- enty-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 res- piratory movements are partly voluntary and partly in- voluntary, 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 respira- tory muscles, these continue for a time to act in an in- voluntary or spasmodic manner, after having "been brought into violent action. Sobbing seems to be pecul- iar to the human species; for the keepers in the Zoologi- cal Gardens assure me that they have never heard a so"b 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 anal- ogy 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 11 * Be la Physionomie,' 1865, p. 126.