The developing child during the germinal stage is called a zygote.

Here's a breakdown:

* Germinal Stage: The first two weeks of prenatal development, starting with fertilization.

* Zygote: The single cell formed when a sperm fertilizes an egg.

The zygote rapidly divides and forms a blastocyst, which then implants in the uterine wall. This marks the end of the germinal stage and the beginning of the embryonic stage.