Surfactant is a complex substance containing phospholipids and a number of apoproteins. This essential fluid is produced by the Type II alveolar cells, and lines the alveoli and smallest bronchioles.
My friends and family say I am obsessive about the subject. Shakespeare had three children. Susannah was born in May 1583, six months after William married Anne (so Anne was pregnant at the time of the wedding). Two years later (1585) the twins Judith and Hamnet (girl and boy) arrived.
The Shakespeare family, then, was in decline as William approached adulthood. It was in the late summer of 1581 that Anne Hathaway, a spinster seven or eight years older than William, discovered she was pregnant with his child.