( ( If ( ( ( even ( a ( small part ) ) ) ( of ( these hormones ) ) ) ( reach ( the ( other fetus ) ) ) ) ) ( , ( ( the quantity ) ( ( could ( be ( large ( relative ( to ( what ( is ( required ( for ( observable ( behavior changes ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (S (NP (NP (RB even) (DT a) (JJ small) (NN part)) (PP (IN of) (NP (DT these) (NNS hormones)))) (VP (VBP reach) (NP (DT the) (JJ other) (NN fetus))))) (, ,) (NP (DT the) (NN quantity)) (VP (MD could) (VP (VB be) (ADVP (RB large) (JJ relative) (PP (TO to) (SBAR (WHNP (WP what)) (S (VP (VBZ is) (VP (VBN required) (PP (IN for) (NP (JJ observable) (NN behavior) (NNS changes))))))))))) (. .)))
If even a small part of these hormones reach the other fetus, the quantity could be large relative to what is required for observable behavior changes.
(ROOT (S (NP (JJ Placental) (NNS mammals)) (VP (VBP give) (NP (NN birth)) (PP (TO to) (NP (ADJP (RB relatively) (JJ large)) (NNS fetuses)))) (. .)))