sper·mat·o·go·ni·um 
(spər-măt′ə-gōnē-əm, spûr′mə-tə-)
(spər-măt′ə-gōnē-əm, spûr′mə-tə-)n. pl. sper·mat·o·go·ni·a (-nē-ə)
Any of the cells that give rise through mitosis to the spermatocytes and are found in the testes of vertebrates.
[New Latin : SPERMATO- + -gonium, seed, cell, reproductive structure of a fungus or plant; see SPERMOGONIUM.]
sper·mat′o·goni·al (-nē-əl) adj.