2.  The duration of pregnancy is from 278 to 280 days, or nearly forty weeks.  The count should be made from the beginning of the last menstruation, and add eight days on account of the possibility of it occurring within that period.  The heavier the child the longer is the duration; the younger the woman the longer time it often requires.  The duration is longer in married than in unmarried women; the duration is liable to be longer if the child is a female.

3.  MOVEMENT.—­The first movement is generally felt on the 135th day after impregnation.

4.  GROWTH OF THE EMBRYO.—­About the twentieth day the embryo resembles the appearance of an ant or lettuce seed; the 30th day the embryo is as large as a common horse fly; the 40th day the form resembles that of a person; in sixty days the limbs begin to form, and in four months the embryo takes the name of foetus.

5.  Children born after seven or eight months can survive and develop to maturity.

[Illustration:  DURATION OF PREGNANCY.]

DIRECTIONS.—­Find in the upper horizontal line the date on which the last menstruation ceased; the figure beneath gives the date of expected confinement (280 days).

Jan. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Oct. 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Jan. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Oct. 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 Nov.

Feb. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Nov. 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Feb. 16 17 18 19 20 21 22 23 24 25 26 27 28
Nov. 23 24 25 26 27 28 29 30 1 2 3 4 5 6 7 Dec.

Mar. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Dec. 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Mar. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Dec. 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 Jan.

Apr. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Jan. 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Apr. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Jan. 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 Feb.

May 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Feb. 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

May 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Feb. 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 Mar.

June 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Mar. 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

June 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Mar. 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 Apr.

July 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Apr. 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

July 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Apr. 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 May

Aug. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
May 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22