The rural and manufacturing co-operatives and credit co-operatives in the Federal Republic of Germany have succeeded in continuously expanding and consolidating their position within the framework of the country's market economy. As the biggest organizations of medium-size enterprises, the co-operatives have adapted to the new circumstances prevailing in an industrialized society and at the same time have kept their obligation to help with development and expansion projects in the Third World. The voluntary character of the organization and co-operative combine to form the key feature of every western style co-operative. The details of co-operative work date back to the life's work of Friedrich Wilhelm Raiffeisen (1818-1888) who, around the middle of the 19th century, encouraged the rural population in Germany to help one another cope with poverty and hardship through self-help, self-administration, and individual responsibility. The report's four sections discuss: the basic features of the co-operative system in the Third World; rural co-operatives in a world-wide link-up; German development aid and self-help promotion; and a model case in The Federal Republic of Germany. (BZ)