What are two gases that animals exchange with heir surroundings?

The Courtin' is a 95 lines long poem. Since it has been written in 1874, it was the end of the Victorian era which the poem illustrates the complexities of the time. The poem shows the mentality war of traditional and modern values of the time in the lights of the love of two main character in the poem. They break the traditional rules and fear the approval of their parents. Lowell describes the courtship amidst this confusion.