Michigan Ornithological Club 21 



is supposed to be the case with some species? Do the old birds or the 

 young lead in the fall migrations? This is a question upon which there is 

 considerable difference of opinion among writers at present, and is a vital 

 point in the recently advanced theory of Capt. G. Reynaud 1 on the orienta- 

 tion of animals, in which he advances the theory of a "sixth sense/' which 

 he calls the "law of retracement" or "law of reverse scent." He says, 2 

 "When the time for departure is come, birds of the same species, inhabiting 

 the same region, come together for the journey. Those that have already 

 made the voyage take the lead and retrace the path by which they came. 

 The younger birds, born since the last journey, confine themselves to 

 following their elders, and when, some months later, it becomes time 

 to return, these are able in their turn to follow in a reverse direction the 

 journey previously made." Here is a question of fact that must be settled 

 by observation before we can seriously consider the theory. Again, Is it 

 the young birds that are most apt to stray from the regular paths of 

 migration ? Does the species in migrating advance as a whole, or is it 

 "like a game of leap-frog," the birds in the rear continually passing those 

 ahead, as a flock of passenger pigeons is said to advance across a field 

 when feeding? How definitely do birds return to the same locality every 

 summer? Do their routes of migration vary from year to year? These 

 and many other questions could, I believe, be settled by a line of study 

 such as I have indicated, and would open the way to a consideration of the 

 little-understood "homing instinct" of animals, which probably reaches its 

 highest development in birds, enabling them to reach a definite destination 

 over hundreds of miles of land and sea, often without any landmark for 

 guidance, even supposing that they make use of such helps. This faculty 

 appears especially remarkable to one who has seen the murres and other 

 water birds of Bering Sea returning through the ever-present fog to their 

 nests on one of the few islands which afford them a home. As the boat 

 approaches land, which is hidden from sight and its presence and direction 

 known to the navigator only by the help of his charts, long, broken lines 

 or smaller flocks of these birds are seen flying rapidly by. There is no 

 hesitation, no uncertainty ; they may swerve aside from curiosity to pass 

 near and inspect the ship, but the flight is then continued in the former 

 direction. What can guide these creatures where the vision is limited 

 to a small expanse of gray water enveloped in cloud? Certainly it cannot 

 be the direction of the wind, as maintained by seme, for the wind does not 

 always blow in the same direction, and may even not blow at all. 



It is not an easy matter to select a species of bird that will meet all 

 the conditions given above as desirable for the one to be studied, but 

 there are several that fulfill a part of them at least. As far as the matter 

 of plumage goes the red-winged blackbird seems to offer as good a subject 

 for easy identification as any, and would also be favorable in other ways; 

 but it is possible that further thought may suggest a better. 



To answer some of the questions propounded above an even more 

 exact method will probably be needed, and it is possible that for this 

 some such plan as that pursued by the United States Fish Commission 

 might be utilized. In order to. get information of the movements of fish 



J Revue des Deux Mondes, CXLVI, 380-402, Translation in Annual Report Smiths. 

 Inst, for 1898, pp. 481-498. 



2 Smiths. Rept. for 1898, p. 490. 



