FIGURE 4.

Left: (Top) Carroll M. Williams. Photo from his memoir in the National Academy of Sciences Memoir collection. (Bottom) Cecropia male abdomen parabiosed to a chilled diapausing Cecropia pupa (left); after 21 days, the “second pupa” had formed and the abdomen had molted to a scaleless adult abdomen (right, arrow) (from the original slides taken by Muriel V. Williams that were used for the black-and-white Figures 3, 4 in Williams, 1963). Center: Diagram of the Cecropia male moth whose corpora allata (CA) synthesize and secrete juvenile hormone (JH) acid and from whose abdomen the “golden oil” that contained JH was extracted (drawing of the moth modified from a figure in Williams, 1958). Right: Reproductive system of a male saturniid moth (modified Figure 1 in Shepherd, 1974). The accessory glands of Cecropia males synthesize JH from the JH acid that is secreted from the CA, then store the hormone (Shirk et al., 1976; Peter et al., 1981).