( He ( ( found ( that ( ( the bacterium ) ( began ( destroying ( ( the walls ) ( of ( the ( blood cells ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VBD found) (SBAR (IN that) (S (NP (DT the) (NN bacterium)) (VP (VBD began) (S (VP (VBG destroying) (NP (NP (DT the) (NNS walls)) (PP (IN of) (NP (DT the) (NN blood) (NNS cells)))))))))) (. .)))
He found that the bacterium began destroying the walls of the blood cells.
(ROOT (S (NP (DT A) (NN lysozyme)) (VP (VBZ destroys) (NP (NNS bacteria)) (PP (IN by) (S (VP (VBG digesting) (NP (PRP$ their) (NN cell) (NNS walls)))))) (. .)))