Regeneration of the Tail-Fins of Fundulus Embryos

1. A study was made of regeneration of the tail-fins and basal plate of Fundulus heteroclitus embryos operated upon prior to the time of hatching. 2. Splitting of the tail-fin anlage does not result in reduplication of the tails. 3. Removal of the entire tail-fin anlage results in no regeneration up to and including the sixty-fifth day after operation. 4. If part of the basal plate is removed with the rays distal to it new rays will appear in seventeen days and the plate will regenerate in fifty days.