J^GERS. 77 



pleasing for a time than the song of tlie lark or blackhird (Mfruht). Every now and 

 tlicn a tern dips into the water, and emerges with a little lisli in its Ijill, wliieli it swal- 

 lows without alighting. In the midst of all this bustle and merriment, there comes 

 gliding from afar, with swift and steady motion, a dark and resolute-looking Itird, 

 which, as it cleaves a i>atii for itself among the white terns, seems a messenger of 

 death. But a few minutes ago he was hut a dim speck on the horizon, or at least 

 some miles away, and now, tmthought of, he is in the very midst of them. Nay, he 

 has singled out his victim, and is pursuing it. The latter, light and agile, attempts to 

 evade the aggressor. It mounts, descends, sweeps aside, glides off in a curve, turns, 

 doubles, and shoots away, screaming incessantly the while. The sea-hawk follows 

 the frightened bird in all its motions, which its superior agility enables it to do 

 witli a]iparent ease. At length the tern, finding escape hopeless, and perlia]is terrificil 

 by the imminence of its danger, tlisgorges part of the contents of its gullet, probably 

 with the view of lightening itself. The pursuer, with all his seeming ferocity, had no 

 designs ujion the life of the poor tern ; and now his object is evident, for he j»lunges 

 after the falling fish, catches it in his descent, and presently flies oft" to attack another 

 bird. In this way the marauder makes his rounds, exacting tribute from all whom 

 he thinks capable of paying it, and not sturdy enough to resist o|>pression. The 

 teaser never fishes for himself on such occasions, although his organization seems to 

 fit him for aquatic rapine, even more than that of the tern or gull. The pirate can 

 neither dive nor plunge, but it swims with ease, and sits lightly on the water, like a 

 gull. The instinct that enables it to select a bird that has .something to spare for its 

 wants is truly surjirising. I have never seen it give chase to a gull or tern, without 

 accomplishing its purpose. It is not a singular case that an animal should be destined 

 to live by the labors of others of different species ; but in the class to which the pirate 

 belongs there are very few instances of such an arrangement. It cannot, however, be 

 said to live without labor, for the trouble of conijielling its unwilling v.assals to dis- 

 gorge is apparently greater than what would abimdantly supply it with honestly 

 obtained food." 



Before closing the history of this bird, we may remark that it breeds almost exxlu- 

 sively near fresh water, though, of course, not so very far from the sea, unless in the 

 neighborhood of a colony of terns or gulls, likewise breeding at an inland lake. We 

 have already, in the introduction, mentioned the remarkable dichiumatism of this 

 species, which has no connection with age, season, or sex, but which seems to be some- 

 what influenced by the geographical distribution, since the dark phase is the most 

 numerous form in the southern part of the range, while in the highest north the bird 

 with the whitish under side is the predominating, and jiossibly the only occurring. 



In the next family, the Larid.e, the horny covering of the bill is continuous, there 

 being no cere or separate piece overhanging the nostrils. The hind border of the 

 sternum is provided with two notches on each side, and the ca'ca are short. The di- 

 vision in two sul)-families has already been mentioned. The first one of these com- 

 prises the gulls and terns, which we, at present, can see no reason for separating, 

 except as subordinate groups. The latter are usually of a slon<lcrer build, and tlie 

 nostrils are mostly i>laeed in the basal half of the bill, while in the gulls they open 

 near the middle, and furthermore, their bill is not hooked at the end, as usually in the 

 gulls, but these differences are only those of degree, antl they run nearly imperceptibly 

 into each other. The po])ular notion as to the characters scjiarating these two grouj's 

 is that the gulls liave an even tail, the terns a forked one ; but while this mark holds 



