1. A method is described for the in vivo and in vitro study of osteogenesis by implanting a modified transparent chamber in half lop-eared rabbits (as originated by Sandison 1928). This method allows the daily observation and photography of the developing bone and the study of its intimate connection with the vascularity of the area.

2. The osteogenetic potential of a variety of substances can also be investigated by this method. The tissue in the chamber can easily be prepared for its final examination by optical and electron microscopy and by other laboratory techniques.