188 THE SCIENTIFIC MONTHLY
result in each one of a series of closely related carbohydrates."* Driesch^'^ has suggested that within the nucleus of the cell is a store- house of these ferments which pass out into the protoplasm tissues and there set up specific activities; and recently it has been suggested that it is hormones which affect certain hereditary determiners in Uie chromatin or germ plasm itself.
In 1849 there was given the first experimental proof of action exer- cised upon an organism by a ductless gland.^'^ Berthold transplanted the testicles of young cocks^ which afterward developed the masculine voice^ sexual desire^ comb^ and love of combat, thus anticipating Brown- Sequardy who committed himself to the view that a gland, ductless or not, elaborated substances essential to the growth and maintenance of the body. Continuing the investigation of the chemical correlation of the activities of animal bodies, Bayliss and Starling proposed the name ^^ hormones {6piihMy to awaken, stir up). Hormone-producing agents develop from certain endocrine organs or glands of internal secretion. The secretion of a gland may act indirectly : e. g,, the influence of the thyroid by way of the thymus upon the activities of the stomach.
The heredity theory proposed by Cunningham*** was based upon the discovery that the connection between the germ cells and the secondary sexual organs, which was supposed to be of a nervous nature, is really chemical. Since hormones from the germ cells determine the development of many other bodily organs, it is possible that hormones due to various cellular activities in the body may act upon the deter- miners in the germ cells which correspond to the tissues from which these hormones are derived. Cunningham's hypothesis suggests a means by which bodily modifications due to environmental and developmental conditions could modify corresponding determiners in the germ cells.
Catalytic action originates in the by-products of single chemical combinations. For example^ the carbon dioxide liberated in cell metabo- lism acts at a distance on other portions of the cell and of the organism.
- 'In a sense, too," observes Abel, "as has been frequently pointed out,
every cell of the body furnishes in the carbon dioxide which it eliminates a hormone or product of internal secretion, since under normal condi- tions the carbon dioxide of the blood is one of the chief regulators of the respiratory center, influencing this center by virtue of its acidic properties."*^' But in the course of evolution certain entire cells and finally groups of cells took on this function of coordinating and corre- lating the activity of the complex organism. Thus certain glands arose.
Among the catalysers are those which accelerate general growth through stimulating specific chemical activities and others which retard
120 Moore, F. J., 1915, p. 170; and Loeb, Jacques, 1906, pp. 21, 22.
ui Wilson, Edmund B., 1906, p. 427.
122 Cunningham, J. T., 1908, pp. 372-428.
"8 Abel, John J., 1915, p. 168.
124 Halsted, William Stewart, 1914, pp. 224, 225.
�� �
