Meanwhile, two or three days before, while returning from St. Mark's, whither I had gone for a day on the river, I had noticed from the car window a swamp, or baygall, which looked so promising that I went the very next morning to see what it would yield. I had taken it for a cypress swamp, but it proved to be composed mainly of oaks; very tall but rather slender trees, heavily draped with hanging moss and standing in black water. Among them were the swollen stumps, three or four feet high, of larger trees which had been felled. I pushed in through the surrounding shrubbery and bay-trees, and waited for some time, leaning against one of the larger trunks and listening to the noises, of which the air of the swamp was full. Great-crested flycatchers, two Acadian flycatchers, a multitude of blue yellow-backed warblers, and what I supposed to be some loud-voiced frogs were especially conspicuous in the concert; but a Carolina wren, a cardinal, a red-eyed vireo, and a blue-gray gnatcatcher, the last with the merest thread of a voice, contributed their share to the medley, and once a chickadee struck up his sweet and gentle strain in the very depths of the swamp--like an angel singing in hell.
My walk on the railway, that wonderful St. Mark's branch (I could never have imagined the possibility of running trains over so crazy a track), took me through the choicest of bird country. The bushes were alive, and the air rang with music. In the midst of the chorus I suddenly caught somewhere before me what I had no doubt was the song of a purple finch, a bird that I had not yet seen in Florida. I quickened my steps, and to my delight the singer proved to be a blue grosbeak. I had caught a glimpse of one two days before, as I have described in another chapter, but with no opportunity for a final identification. Here, as it soon turned out, there were at least four birds, all males, and all singing; chasing each other about after the most persistent fashion, in a piece of close shrubbery with tall trees interspersed, and acting--the four of them--just as two birds are often seen to do when contending for the possession of a building site. At a first hearing the song seems not so long sustained as the purple finch's commonly is, but exceedingly like it in voice and manner, though not equal to it, I should be inclined to say, in either respect. The birds made frequent use of a monosyllabic call, corresponding to the calls of the purple finch and the rose-breasted grosbeak, but readily distinguishable from both. I was greatly pleased to see them, and thought them extremely handsome, with their dark blue plumage set off by wing patches of rich chestnut.