DICTIONARY OF TERMS
BLASTULA

Pronunciation: BLAS-tu-la.  

Etymology: The term is derived from the Greek root, blastos (βλαστός) which means a sprout, bud, or shoot.  The -ula ending is the dimuitive Latin ending.  So, it literally means little sprout or bud.  The reference is to the blastula being the "bud" from which an animal develops.

The blastula is a hollow, fluid-filled ball of cells that develops from the zygote of Metazoans.  From here, the blastula may develop into a gastrula by the formation of a blastopore.

Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates