THE GROWTH OF COUNT MONTBEILLARD'S SON

Parents often record the growth of their children by marking increases in height on a door or wall. So it was for Count Philibert Guéneau de Montbeillard, who during the period 1759–1777 measured the height of his son at regular intervals over the first 18 years of his life. The Count's measurements show a steady increase in height (Figure 5.1) throughout these years. The curves showing increase in size (W) over time (t) represent the traditional way that growth is depicted, and the attainment of a respectable size is what matters to a doting parent. Sadly the Count's son ended his life prematurely on the guillotine at the behest of Robespierre.

For the student of the physiology of growth, the cumulative growth curve is uninformative, revealing little about growth as a process (Figure 5.1). The curve hardly changes in slope, so shows little obvious change in rate. Much more informative is the curve showing changes in growth rate over time (Figure 5.1).