This research is a longitudinal, ethnographic study that focuses on mealtimes with one boy from 9 to 78 months of age in a day-care center in Japan. It looks at routine interactions between a child, his nursery teachers, and the environment, which is a shared and mutually available communicative space between participants in collaboration. The aim of this study is to clarify how the meal as a learning problem is "solved," especially with young children whom the teacher cannot instruct verbally, and how the environment in which this takes place affects the process and is used in collaboration. The first part, a diachronic illustration of the child's environment, in which all materials are organized as a total system to constrain his action, demonstrates the dynamic relation between his actions, the nursery teachers' actions, and the environment. The second part presents the findings of a microanalysis of the interaction between a nursery teacher and the boy at 15 months, which is a critical transitional time from other-assisted to self-organized eating. It shows the close interdependence between the child's environment and the teacher's way of caring for him. The teachers generally used environmental modifications to assist his eating and to channel his actions toward their preferences. This study has demonstrated that children can learn much through an intentional arrangement of an artificial environment. (author abstract)