( They ( only ( ( breed ( ( ( on ( ( the continent ) ( of Antarctica ) ) ) and ) ( on ( some ( of ( the ( ( most southerly ) islands ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (PRP They)) (ADVP (RB only)) (VP (VBP breed) (PP (PP (IN on) (NP (NP (DT the) (NN continent)) (PP (IN of) (NP (NNP Antarctica))))) (CC and) (PP (IN on) (NP (NP (DT some)) (PP (IN of) (NP (DT the) (ADJP (RBS most) (JJ southerly)) (NNS islands))))))) (. .)))
They only breed on the continent of Antarctica and on some of the most southerly islands.
(ROOT (S (NP (NNP Antarctica)) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN continent)) (PP (IN without) (NP (NNS amphibians))))) (. .)))