Development
The development of the vocal sac is different in most species, however they mostly follow the same line. The development of the unilobular vocal sac begins with two small growths on the floor of the mouth. They begin to grow, until they form two small pouches. The pouches expand until they meet in the centre of the mouth, and form one large cavity, which grows until it is fully developed.
Read more about this topic: Vocal Sac
Famous quotes containing the word development:
“For the child whose impulsiveness is indulged, who retains his primitive-discharge mechanisms, is not only an ill-behaved child but a child whose intellectual development is slowed down. No matter how well he is endowed intellectually, if direct action and immediate gratification are the guiding principles of his behavior, there will be less incentive to develop the higher mental processes, to reason, to employ the imagination creatively. . . .”
—Selma H. Fraiberg (20th century)
“The American has dwindled into an Odd Fellow—one who may be known by the development of his organ of gregariousness.”
—Henry David Thoreau (1817–1862)
“John B. Watson, the most influential child-rearing expert [of the 1920s], warned that doting mothers could retard the development of children,... Demonstrations of affection were therefore limited. “If you must, kiss them once on the forehead when they say goodnight. Shake hands with them in the morning.””
—Sylvia Ann Hewitt (20th century)