This study was undertaken to determine the quantitative changes occuring in the weights of the bursa and thymus in chicks hatched from eggs in treatment in varying levels of testosterone propionate. The data obtained in the presented investigations
were described being separated into two parts.
1) Dipping eggs in TP solution of 640 mg. or 1200 mg. and TP injected eggs of 0.5 mg. or 1.0 mg. siginificantly reduced bursa size and weight at hatching. Especially, TP 1.0 mg. injected eggs is remarkable reduction as compared into the other experiments. On the other hand, the development of the thymus showed a tendency to no effects on chicks hatched from eggs in TP treatment.
2) Number of the chicks hatched from dipped in TP solution was observed small in average number compared with control. Chick embryos in the still-development in TP treatment various deformities were observed.