Allotropy
the property possessed number of different forms. An example ALTERNATION OF GENERATIONS 56 is carbon, which appears pure in diamonds and also in graphite. ALTERNATION OF GENERATIONS, a phenomenon occurring in both plants and animal organisms in which two or more forms or distinct stages of development and reproduction appear in one life cycle, the original parent form not being directly reproduced from seed or eggs, but first giving rise to some other form out of which the original form is ultimately reproduced. The term is derived from the alternation of sexual and In ferns and mosses the spores given asexual generations within one life cycle. off do not directly produce new young plants as do the seeds of flowering plants, but instead they give rise to distinct heart-shaped or leaf-like plant forms, which in their turn produce sexual organs and ultimately reproduce the parent form. Alternation of generations occurs not only in plants, but in certain of the lower forms of animal life, as in the coelenterates and certain worms and insects.
AMERICAN CONSTRUCTION COUN- CIL, a conference association formed in 1922 by architects, engineers, contractors, representatives of construction labor, manufacturers, and representatives of all government and public utility construction departments, for the purpose of establishing better standards and principles for the American construction industry, correlating efforts in the field of construction, and improving the whole service which the industry renders the public. The first president of the Council was Franklin D. Roosevelt. AMERICAN FARM BUREAU FED- ERATION, an organization of American farmers to promote, protect, and represent the economic, social, and educational interests of the farmers of the nation, and to develop agriculture. It is composed of state farm bureau federations and state agricultural associations based on the farm bureau plan. Local farm bureaus were originally formed to cooperate with the agricultural experts or advisers sent out by the U. S. Department of Agriculture and by various state agricultural colleges. The movement grew rapidly during the war, when a county agent or agricultural expert was placed in every county of the nation.
There were in 1922 almost 2,000 county farm bureaus, and these were united for larger purposes in 46 state farm bureau federations. A number of state bureaus are engaged in such activities as the large-scale production of fertilizers or other farmers' supplies, while others act ARGHAN as marketing agencies, and all watch over their members' interests in securing needed legislation, etc. In 1920 all the state farm bureaus united in a National Farm Bureau Federation. National headquarters were established in Chicago and a legislative service at Washington, D. C. The farm bureaus are supported by dues of members, the membership including both men and women. State and federal appropriations for agricultural extension work amount to only a part of the expense of this work, the remainder being borne by the county farm bureaus.
Among the accomplishments of the National Federation during the first two years of its existence, the advancement of cooperative marketing stands foremost. A number of powerful organizations have already been formed or are now being formed for the marketing of tional all the great staple products. The legislative service maintained at Washington watches out for the farmers' interests on all questions. Its program is presented through the Farm Bloc in Congress, which was organized in the office of the Farm Bureau Federation.