Effect of serial transplantation on the growth of neonatal pancreas in the hamster

Neonatal pancrease was implanted in the cheek pouches of cortisone‐treated normal and diabetic hamsters. They were permitted to remain in these sites for: 5–6; 13; 15–16; 19–20; 26 and 36 days, at which times small pieces were transferred to the pouches of cortisone‐treated secondary hosts. The size of the growth was measured at intervals in both hosts. After a final measurement, 23–25 day after transplant, the graft in the secondary host was removed and prepared for histological study. Growth in the secondary hosts was compared both with that found in a large group of similarly‐treated hamsters and with the growth of this same material while it grew in the primary host. In general, except for one or two brief time periods, there was either no significant size difference or the growth in the secondary host was significantly less than in primary hosts. Histological studies of transplants from secondary hosts showed very poor pancreatic differentiation. In no case was recognizable islet tissue found in the pouches of secondary hosts.