BIRTH, or LABOR, in physiology, is the act by which a female of the class mammalia brings one of her own species into the world. When the foetus has re mained its due time in the womb, and is in a condition to carry on a separate existence, it is extruded from its place of confinement, in order to live the life which belongs to its species, independ ently of the mother. The period of ges tation is very different in different ani mals, but in each particular species it is fixed with much precision. At the end of the 39th or the beginning of the 40th week, the human child has reached its perfect state, and is capable of living separate from the mother; hence follows in course its separation from her, that is, the birth. An artificial birth is that which is accomplished by the help of art, with instruments or by the hands of the attendant. Premature birth is one which happens some weeks before the usual time, namely, after the seventh and be fore the end of the ninth month. Late birth is a birth after the usual period of 40 weeks. Although this is considered the usual time for legitimate births, the practice of the English law courts is to allow a longer time when the opinions of the faculty, or the peculiar circum stances of the case, are in favor of a protracted gestation.
the proportion of births in a given number of inhabit ants. For some years it has been evi dent to students of vital statistics that the birth-rate was steadily decreasing in nearly all European countries.
Table No. 1 gives the births and birth rates in the birth registration area of the United States from 1915 to 1918, in clusive. The registration area includes only those States in which such records are kept. Table No. 2 gives the birth rate in the United Kingdom for the years 1913, 1917, and 1918. These years are selected in order to show the effect of the World War on the birth-rate in Great Britain. Birth-rates for other countries since the end of the World War are not available, but it may be stated in gen eral that the effect of the war was to reduce greatly the rate in all countries which participated in it.
Births and rates per 1,000 population in the birth registration area of the United States for the years 1915 to 19184