A Cyclic Change in the Frequency of the Degenerating Spermatogonia in the Rat

The cyclic change of the frequency of the degenerating A spermatogonia at stage XII in Wistar rats was studied by the technique of hemicastration. There were negative correlations of the frequency of degenerating cells in the testis removed and the testis remaining 4 and 12 weeks after hemicastration. Eight weeks after the operation, at the midpoint of 4 and 12 weeks, the values were almost equal to those at the operation. The frequency of the degenerating A spermatogonia at stage XII is changing within a certain limit and the cycle is nearly 8 weeks.