Technic for Photographing Early Cleavage Stages of the Hen's Egg

Abstract

Altho photographs have been secured of early cleavage stages in the pigeon's egg, no photographs of corresponding stages of development of the hen's egg have been published. Satisfactory photographs of early cleavage stages of the hen's egg have been difficult to obtain in the past because of the indistinctness of the furrows and the lack of contrast between them and the remainder of the blastodisc. The indistinctness of the cleavage furrows in the hen's egg as compared with those of the pigeon's egg was recognized by Patterson (1910) who, after having studied both types of eggs, states (p. 109): “The lack of a furrow is the cause of the indistinctness of the early cells. In this respect, the early cleavages of the hen's egg differ greatly from those of the pigeon's egg, for in the latter their clearness is such as to permit photographing the living cells, while in the former photographs are impossible, except in a few cases”.