Humoral and Tissue Factors in Tissue Differentiation

Abstract

ABSTRACT It was shown by Gaillard (1931,1935,1942) that pure strains of fibroblastic cells are very sensitive to those differences in the culture media which go hand in hand with the process of ageing of the donors used for preparing the media, the dimensional growth of the explants being used as a criterion. Moreover, strains of different origin reacted in a different way, thus demonstrating that cells which are morphologically alike can behave quite differently in vitro. When cultivating such a pure strain derived from the anlage of the frontal bone of a 15-day-old chicken embryo successively in a range of culture media prepared from 10-, 15-, and 18-day-old embryos, serum from a newly hatched chicken, and serum from an adult hen, histological bone formation occurred after 12 days of cultivation. This means that the realization of this obviously existing potentiality depended on the composition of the successive media.