This question involved Latin.
Ostendere : Ostensible :: (D) Videre : Introspection
Argos was Odysseus's hunting dog and his faithful pet. Even when its owner left it to fight in the battle of Troy, it waited for him for years and years, with unwavering loyalty. When Odysseus finally returned to Ithaca, disguised as a beggar, a very aged Argos recognized him and felt incredibly happy to see him again, dying not long after, as it could finally fulfill its wish of seeing him once again. Argos is included in the poem to represent undying loyalty.
The first 8 lines make the poem sound like bad news, and the word "contagious" sets the mood for the poem. The pastoral tradition celebrates the beauty of the natural world and the simple pleasure of living in the countryside. However, the first 8 lines of the poem seem to claim the exact opposite, with words like "contagious" "surge" "cold", and "waste."