‘The Crow’ and the ‘hemlock tree’ are generally considered to be inauspicious and ominous symbols. How does the poet use them so?

The question seems to be referring to a specific poem that isn't mentioned, but I'll assume it's Edgar Allan Poe's "The Raven" and Henry Wadsworth Longfellow's "The Hemlock Tree," as these are well-known poems featuring these symbols.

1. The Crow: In "The Raven," the crow (or raven) is used as a symbol of death and despair. The raven is a bird associated with bad omens and death in many cultures, and Poe uses this to his advantage in his poem. The raven's constant repetition of the word "Nevermore" serves to remind the narrator of his lost love, Lenore, and his despair at her death. The raven's presence and its ominous message contribute to the dark, melancholic atmosphere of the poem.

2. The Hemlock Tree: In Longfellow's "The Hemlock Tree," the hemlock tree is used as a symbol of bitterness and sorrow. Hemlock is a poisonous plant, and its use in the poem could be seen as a metaphor for the poisonous effects of sorrow and regret. The speaker in the poem talks to the hemlock tree as if it's a friend, sharing his sadness and loneliness with it. The hemlock tree, with its dark, poisonous connotations, thus becomes a symbol of the speaker's inner turmoil.

In both poems, these symbols are used to convey a sense of despair, sorrow, and death, contributing to the overall dark and melancholic tone of the poems.