In Mexico, a primary agent for social change continues to be agrarian reform. However this is no longer restricted to the reformation of outdated, pre-Revolution land tenure systems. Today, it is necessary to formulate effective and feasible agrarian policies which will help to meet Mexico's current needs for financial, technological and social development and which will solve problems created by the new land tenure structure. It is thus that the Mexican government has launched various new programmes which are intended to facilitate and enhance the development of the ejido system of land tenure within the country. The use of the ejido as a means of distributing and holding lands has had problematical success. Because peasants' rights to ejido lands are usufructuary, they have no title to the land. As a result, the land cannot be used as collateral for securing loans for agricultural production from private lending institutions. To aid the ejidatarios, the government has established specific national credit banks whose function it is to lend money to groups of peasants who in turn assume a collective responsibility for the debt incurred. This study examines credit groups in two colonies along the Candelaria River, Campeche, Mexico, to determine the impacts of these groups on agricultural landscapes in the colonies. As somewhat of a control, in order that a valid basis for comparison might be established, a third community, possessing a similar physical environment and organizational framework, but lacking credit groups, was also studied. The intent of the study is to investigate how the function of credit groups affects land area cultivated, methods of agriculture, types of crops grown, and the socio-economic well-being of the communities in the field area. In order to undertake the study, it was first deemed necessary to review the evolution of land tenure systems in Mexico with a view towards understanding the framework within which the Mexican peasant is intended to carry out his agricultural activities. Three critical social factors were then identified as affecting the unity and cohesion found in the credit groups, and ultimately within the communities themselves. These factors were the background of group and community members, allegiance to the group or community, and the leadership quality found in the field area. Interviews were then carried out, with the majority of people interviewed fitting into two broad categories, either peasants who were eligible to receive or in fact were receiving agricultural credit, or peasants who were ineligible to receive this aid. Additional information regarding the characteristics of the field area and the operation of the credit groups was obtained from credit banks serving the area, from the Department of Agrarian Affairs and Colonization, the Centre of Agrarian Studies, and other relevant sources. The study indicates the agricultural methods and types of crops grown in the field area are directly affected by the credit groups and result in agricultural landscapes which bear a strikingly different aspect from those effected by peasants who do not benefit from credit aid. Nevertheless, this is a superficial difference. The land area cultivated and, perhaps more important, the economic well-being of those who receive credit aid versus those who do not receive such aid, does not appear to differ significantly. This similarity in these latter two variables is shown to be attributable in part to the diverse and, in some cases, incompatible backgrounds of some residents of the field area, to varying degrees of allegiance and commitment to the credit groups and communities studied, and to differing qualities of leadership within the groups and communities. Equally important was the finding that the ejido system of land tenure was unacceptable to the colonists who were interviewed In light of the impact of the social factors on the field area, and the apparent disteem for the actual framework within which the residents of the colonies exist, the validity of colonization schemes such as that along the Candelaria becomes questionable. Consequently, implications for changes in the current ejido system of land tenure are discussed in the final chapter of the study. If the system itself is not abandoned, as it might well be modifications to it are certainly imperative. / Arts, Faculty of / Geography, Department of / Graduate