ABSTRACT
G. Pincus described the transfer of eggs cultured in vitro to the oviducts of pseudopregnant does, but no offspring were obtained "for a number of reasons, chiefly technical". Chang has published 335 papers including several concerned with highly original and fundamental aspects of egg transfer. Egg recovery is an integral part of the egg transfer procedure. Broadly speaking, there are two main approaches to egg recovery: in vivo, either by flushing the tract at laparotomy or nonsurgically, and by flushing the appropriate region of the excised tract at autopsy or after surgery. In collaboration with E. V. Enzmann, G. Pincus used egg transfer to determine whether rabbit eggs "fertilized" and cultured in vitro might give rise to normal offspring. In species like the rabbit in which ovulation is nonspontaneous and easy to arrange, either by mating or the injection of human chorionic gonadotropin or Luteinizing hormone-releasing hormone, synchronization presents no problem.
