Final answer:
The first and fourth excerpts exhibit themes associated with Realism, specifically Naturalism, while the third excerpt's intense emotion and mythological references suggest Romanticism. The second excerpt's classification is less clear but leans towards Realism.
Step-by-step explanation:
Classifying Literary Periods
When classifying the provided excerpts into the appropriate literary period, we must consider the thematic content and stylistic features that define Romanticism and Realism. Romanticism, emerging in the late eighteenth century, celebrated freedom of expression, nature, and the emotional experiences of individuals. In contrast, Realism, dominant in the late nineteenth and early twentieth centuries, focused on accurate depictions of everyday life and often explored social issues in a more stark and gritty manner.
"He had never seen dogs fight as these...": This excerpt suggests a focus on nature and the animalistic aspects of existence, aligning it with Naturalism, therefore, and by extension, with the broader purview of Realism.
"In one of the mighty triumphs given to a Roman general...": This excerpt lacks context to properly associate it with a particular period. However, given the historical and ceremonial detail, it seems more aligned with Realism, given its attention to detail.
"Oh, God! to sail with such a heathen crew...": The intense emotion and reference to the natural and mythological ('the sharkish sea' and 'demigorgon') strongly suggest Romanticism.
"for of the many Southland dogs he had known...": With an emphasis on survival in a harsh environment, this excerpt also leans towards Realism, particularly Naturalism, which depicts the struggle against unforgiving circumstances.