Vol. xxiii.] 82 



range, but witliin that radius their aim is good. 

 The supply of evil-smelling ammunition seems to be 

 inexhaustible. 

 25 & 26. A Fulmar in full flight turning to look at the 

 intruder, it being again noticed (as in the case of 

 the Gannet) that the tail is depressed and expanded 

 into a perfectly shaped fan, in order to lessen the 

 speed while passing. A frequent device adopted by- 

 birds for temporarily lessening their speed, whilst 

 gliding past some object they wish to scrutinize, is 

 the lowering and expanding of the feet, 



27. In the case of a Kittiwake {Rissa tridactyla) the feet 



were shown to be used for quite another purpose 

 during flight, namely, that of acting as an auxiliary 

 steering apparatus. When used solely for this 

 purpose, as a rule one foot only is employed at a 

 time, and is thrust out fully expanded on the side 

 to which the bird wishes to turn. 



28. A native of St. Kilda in the act of catching a Puffin 



{Fratercula arcticd). 



29. An intruding Puffin on the edge of a rock already 



reserved and occupied by the owners of three 

 neighbouring burrows. The picture plainly shows 

 the haughty resentment on the part of the original 

 tenants, and the grave doubts as to his reception 

 on the part of the intruder. 



30. Showing the intruder gone and a much pleasanter 



expression on the faces of the rightful owners. 



It was also to be noted in this slide that two of 

 the birds were comfortably sitting on their tarsi, 

 though their bodies were not held so vertically as is 

 characteristic of the other Auks. 



31. A group of Puffins on the top of a cliff, and a bird just 



swooping down to alight. Here, again, the lowered 

 and fully expanded feet, acting as brakes, were 

 conspicuous, while the former remarks about the 

 expansion of the wings (Nos. 2 & 3) were borne out 

 by a bird about to take flight. 



