( it ( ( is ( ( the sum ) ( of ( knowledge ( relating ( to ( blood ( and ( lymph vessels ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP it)) (VP (VBZ is) (NP (NP (DT the) (NN sum)) (PP (IN of) (NP (NP (NN knowledge)) (VP (VBG relating) (PP (TO to) (NP (NN blood) (CC and) (NN lymph) (NNS vessels)))))))) (. .)))
it is the sum of knowledge relating to blood and lymph vessels.
(ROOT (S (NP (JJ Lymph) (NNS vessels)) (VP (VBP are) (PP (IN like) (NP (NN blood) (NNS vessels))) (, ,) (SBAR (IN except) (S (NP (PRP they)) (VP (VBP move) (NP (NP (NN lymph)) (PP (RB instead) (IN of) (NP (NN blood)))))))) (. .)))