Abstract
This paper describes some genetical results on the acid-phosphatase type of larval blood in the silkworm. Five fundamental types of acid-phosphatase have been found in the various strains investigated. The acid-phosphatase isozymes are under the control of codominant allelic genes, BphO, BphA, BphB, BphC and BphD, and they show different migration rates in agar-gel electrophoresis.