William Erasmus Darwin
William Erasmus Darwin ( 27 December 18398 September 1914 ) was the first-born son of Charles and Emma Darwin , and the subject of psychological studies by his father . 
<triplet> William Erasmus Darwin <subj> Charles <obj> father <subj> Emma Darwin <obj> mother <triplet> Charles <subj> William Erasmus Darwin <obj> child <subj> Emma Darwin <obj> relative <triplet> Emma Darwin <subj> William Erasmus Darwin <obj> child <subj> Charles <obj> spouse