We being with a description of seeds in a dry pod, making a ticking sound. The sound is compared with "faint iambics" that seem to pale in comparison to the "symphony" made by a pine tree.
Then we learn about a whole slew of poetic forms that, as it turns out, don't have anything much to say, other than essentially "time flies when you're having fun." Our speaker, it turns out, has been blind to the true life that has surrounded him in his village.
He wraps up the poem by returning to the ticking of those seeds, those "little iambics" which seem all the smaller when compared to the "roar[ing]" of the poetic greats like Homer and Walt Whitman.