Complex sentence: Vendler observes that Dickinson wrote two versions of the middle of the poem-the second version (the one she sent to friend Thomas Higginson) places no punctuation after "head" and a period after the word "cautious".
Split into simpler sentences: Vendler observes that Dickinson wrote two versions of the middle portion of the poem. The version she sent to friend Thomas Higginson has no punctuation after "head" and a period after the word "cautious".