Aberrant lipogenesis is a phenomenon which has been described by Cogan and Kuwabara in the first four articles of the present series.1-4 The term "aberrant lipogenesis" refers to the formation of fat by tissues or cells which do not ordinarily form fat. Although later shown to be a very general phenomenon, aberrant lipogenesis was first described in the rabbit cornea. Since that tissue has been used in the present experiments, corneal lipogenesis will be described more fully. Sections or "buttons" were cut from fresh rabbit corneas and placed in a medium of serum and sodium oleate (2 mg. per milliliter). The buttons were incubated at 37 C for varying lengths of time and then sectioned in the frozen state and stained with hematoxylin Sudan. Sudan-positive droplets were then found to be present in both epithelial and stromal cells. When incubation periods as long as 48 hours were used, the