Hormones

Defines hormones, tells of their production, and explores the function of several important hormones in animals. Investigates the way in which the pancreas receives information that enables it to secrete pancreatic juice at the proper time. Presents models of phenylalanine, thyroxin, and the steroids--estrone and testosterone--and points out the effects of these three groups of hormones on animals. Using a rooster and a capon shows the difference hormones may make in poultry. Follows with a discussion of the insect prothoracic gland and the corpus allatom and their effects upon the control of molting. Diagrams the pituitary and cites its control in reproduction. Discusses the involvement of hormones in the preparation for reproduction in the white crown sparrow.