112 The Wilson Bulletin — No. Gl. 



September S, 1005, Klugth noted a few iudividnals, and the next year 

 it put in an appearance September 17, increasing to common on the 

 20th, remaining so until our late visit, October 14, when there were 

 still nuuil)ers present. The Ruby-crown has (piite a distinctive 

 habit of flitting its wings while iiausing for a moment between its 

 short flights from bough to bough in the trees. By this little trait 

 it can often be recognized from the Golden-crown, when phases of 

 plumage render it almost indistinguishable from that species. It 

 usually reserves its vocal efforts for the silent northern woods ; but 

 once in a while it does favor us Southerns with a few extracts of 

 its part in the wild northern symphony ; and we are surprised at 

 so nuicli richness of tone, sweetness of melody and strength of voice 

 comlnned in so small a compass. 



199. *PoUoptila Cd'ndcd — Blue-gray Gnatcatcher. 



May 14, 1905, the Blue-gray Gnatcatcher was common on the 

 Point. We did not meet it in si)ring again luitil May 31, 1907, when 

 two were noted August 25. They became common the next day, re- 

 maining fluctuatingly so iintil September 2, after which tliey gradu- 

 ally thinned out to the time of our departure the Gth. The morning 

 of the 5th we were stationed on the lookout tower at the end of the 

 Point when we saw a couple flying outwards, working from tree 

 to tree, and at last vanishing in the last bush towards the final sand- 

 spit. There was a heavy head wind blowing, bathing the shores with 

 a line of breakers, against which Swallows and Martins were mak- 

 ing steady and calm headway. Evidently the Gnatcatchers tried the 

 passage also, for a few minutes later we saw them returning down 

 the wind from over the water as if unable to make it. They came 

 in, facing the wind and blowing backwards. When they reached the 

 land they turned a little off the wind, increasing their efforts at the 

 same time. The result was that they held their own in the direction 

 in which the wind was blowing, but were carried gradually over 

 sideways to the shelter of some heavier hard-wood trees, into which 

 they plunged and, we presume, rested. We mention this litle epi- 

 sode, as it may have some bearing on the present "Beam Wind" 

 theory of migration. We have often taken advantage of this very 

 same maneuver in rowing a boat across the course of a heavy wind 

 or current. Hold the boat a little more than three parts faciug the 

 stress and work .just hard enough to keep from being swept away 

 and you will be surprised at the rapid progress made in a direction 

 at right angles to that of the antagonistic force, and at a remark- 

 ably small expenditure of labor. That birds should take equal ad- 

 vantage of so obvious a principle is not surprising, and it may be 

 oue of the explanations of their apparent preference for migrating 

 with a "Beam Wind." It would have an additional advantage also 

 of blowing their feathers down closer to the body at all times and 



