( ( embryo sac ) ( ( embedded ( in mamelon ) ) . ) )
(ROOT (S (NP (NN embryo) (NN sac)) (VP (VBN embedded) (PP (IN in) (NP (NN mamelon)))) (. .)))
embryo sac embedded in mamelon.
(ROOT (S (NP (NP (DT The) (JJ amniotic) (NN sac)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBD was) (VP (VBG sitting) (PP (IN on) (NP (NP (NN top)) (PP (IN of) (NP (DT the) (JJ flat) (NN embryo))))))))) (, ,)) (VP (VBZ envelops) (NP (DT the) (NN embryo)) (SBAR (IN as) (S (NP (PRP it)) (VP (VBZ folds))))) (. .)))