( Stebbins ( ( ( ( ( ( ( was ( intrigued ( by ( ( ( the ( reptilian ( third eye ) ) ) , ) ( ( an organ ) ( that ( ( ( does n't ) actually ) see ) ) ) ) ) ) ) , ) but ) ( senses ( ( light and ) heat ) ) ) and ) ( is ( connected ( to ( ( the ( pineal gland ) ) ( in ( the brain ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Stebbins)) (VP (VP (VBD was) (VP (VBN intrigued) (PP (IN by) (NP (NP (DT the) (JJ reptilian) (JJ third) (NN eye)) (, ,) (NP (NP (DT an) (NN organ)) (SBAR (WHNP (WDT that)) (S (VP (VBZ does) (RB n't) (ADVP (RB actually)) (VP (VB see)))))))))) (, ,) (CC but) (VP (VBZ senses) (NP (NN light) (CC and) (NN heat))) (CC and) (VP (VBZ is) (VP (VBN connected) (PP (TO to) (NP (NP (DT the) (JJ pineal) (NN gland)) (PP (IN in) (NP (DT the) (NN brain)))))))) (. .)))
Stebbins was intrigued by the reptilian third eye, an organ that doesn't actually see, but senses light and heat and is connected to the pineal gland in the brain.
(ROOT (S (NP (NNS Brain) (CC and) (NNS eyes)) (VP (VBP are) (S (NP (DT the) (NNS organs)) (VP (VB work) (PRT (RP together)) (S (VP (TO to) (VP (VB allow) (S (NP (PRP us)) (VP (TO to) (VP (VB see)))))))))) (. .)))