The Collaborative International Dictionary of English v.0.48:

Germogen \Ger"mo*gen\, n. [Germ + -gen.] (Biol.)
   (a) A polynuclear mass of protoplasm, not divided into
       separate cells, from which certain ova are developed.
       --Balfour.
   (b) The primitive cell in certain embryonic forms. --Balfour.
       [1913 Webster]