DEVELOPMENT OF FERTILIZED TUBAL RABBIT EGGS IN DIFFUSION CHAMBERS IN VIVO

Summary. Fertilized tubal rabbit eggs were transferred to millipore filter chambers (mfc). In one series the eggs were transferred at the two- or four-cell stage to a mfc which was first placed intra-abdominally and 48 hr later moved to the uterus of the same animal. After 24 to 48 hr under these conditions egg development was significantly retarded compared with the controls. In a second series, fertilized eggs recov-ered from the Fallopian tube at 65 to 70 hr were transferred to a mfc which was placed within the uterus of the same animal for 2 days. These eggs developed into expanding blastocysts, though smaller than the controls. The results suggest the existence of a tubal factor necessary for eggs to develop into expanding blastocysts