Abstract
In this paper I will compare two conceptions of basic elements or units of living organisms from the second half of the nineteenth century: Goodsir’s cellular centers and Bütschli’s protoplam. The comparison will be made from the proposition of a nucleoplasmic form, and the referred conceptions are historical expressions of this general form. The nutrition center is a form that combines the functions of nutrition, germination and reproduction, responsible for the production of tissues, organs, tumors and the whole organism from the fertilized egg. Microscopic foams produce organic differentiation through dynamic stabilization of the surface tension between the alveoli. I will conclude critically by discussing the relationship of these two expressions in terms of their continuity or exhaustion as scientific achievements of the biology of the period cited.