POSITIONS ASSUMED BY BIRDS IN" FLIGHT BEETHAM. 435 



In plate 1, figure 1, the gannet has not even risen to its feet prior 

 to lifting the wings, but is sitting on the edge of the nest. The 

 apparent leg supporting it on the near side is a delusion, for instead 

 of being the metatarsus, as it seems, it is really the closed webbed 

 toes hanging downward from the raised and hidden leg, only the 

 claws really touching the nest. The reason for this peculiar position 

 is the newly-hatched chick, hardly discernible, lying in the nest, 

 which would inevitably have been crushed had the bird rested on its 

 expanded foot. 



This raising of the wings preparatory to diving forth is perhaps 

 more convincingly shown in figure 2, as the photograph is taken 

 from a point on the same level as the bird, and shows the wings 

 held up far above the bird's head. This picture, as also figure 1, 

 embraces another and more important point — that the unfolding or 

 straightening of the wing takes place, if again there is no extreme 

 haste, subsequent to the raising. This especially refers to the 

 pinion. 



It will be noticed that although the humeri are raised almost to 

 meeting above the back (pi. 1, fig. 2) the ulnse are not fully extended 

 and in line with them, while the pinions are little divergent from the 

 latter, still making an acute angle with them. Casually one might 

 have expected that, had there been any precedence, the pinion 

 being the most important factor, would have been the first to assume 

 the position requisite for flight, but if these two photographs be 

 carefully examined the reverse appears to be the case. In short, it 

 may be said that the unfolding of the units of the wing seems to be 

 sequential, starting with the humerus, and not simultaneous. 



This is, I fear, directly at variance with the writings of many 

 leading ornithologists and anatomists, and I can only put forward the 

 photographs in support of my observations. Undoubtedly the 

 arrangement and articulation of the wing-bones appear to indicate 

 that the unfolding will take place mechanically throughout on any 

 one part being extended, but laboratory theories, however much 

 they may be upheld by inanimate evidence, can not pass unchallenged 

 when they are found to be in apparent contradiction to observation 

 of the living action supported by corroborative photographs. 



In plate 2, figure 1 shows the bird at the very moment it is diving 

 from the cliff, only the tips of its toes touching the rock, and it will be 

 noticed, as intimated before, that the slope of the body is strongly 

 upward. The wings have not even yet been fully straightened. 

 This final unfolding and stiffening appears, so far as I can ascertain, 

 to take place at the very moment of departure, and had this photo- 

 graph been taken a minute fraction of a second later it would no 



