364 Mr. W. P. Pycraft on the 



its tip ; and if so^ it may be asked : Is the wing-area at this 

 stage sufficient in the case of Opisthocomus to transform a 

 fall into flighty or in the Fowl, having approximately the 

 same wing-area, to enable it to rise from the ground if 

 pursued by an enemy ? By way of answer I would refer to 

 Pettigrew's experiments (10) on flight made upon the Common 

 Sparrow. Of one of these he writes, " Detached the half of 

 the secondary feathers and a fourth of the primary ones of 

 either pinion in the long axis of the wing. Flight in no wise 

 impaired." Again, " Detached rather more than a third of 

 both primary and secondary feathers of either pinion in the 

 long axis of the w^ing. In this case the bird flew with 

 evident exertion, but was able, notwithstanding, to attain a 

 very considerable altitude.'" As a result of his experiments 

 he came to the conclusion that " tlie wing-area is, as a rule, 

 considerably in excess of what is actually required for the 

 purposes of flight.'^ The wing-area of the first of these two 

 experiments which I have quoted seems to correspond roughly 

 to that which obtains in the nestling Opisthocomus (PI. XI. 

 fig. 3) (stage 5) and of the Fowl (PI. XI. fig. 1), and thus 

 serves to support my interpretation of the somewhat puzzling 

 facts we have been discussing. 



Finally, in connection with this subject, I would draw the 

 attention of my readers to the fact that iu the Galli the 

 remiges developed during the nestling period are replaced by 

 others before the bird has quite reached maturity, whilst 

 usually the original remiges are retained during the first 

 year of life. Now, so far as I know, we are yet in ignorance 

 as to whether (1) all the remiges are so replaced, or whether 

 (2) the distal (mid-digital and jjre-digital) remiges, and per- 

 haps even the cubitals, are retained. 



A more careful investigation of this point may possibly, 

 by revealing new facts, show that the theory of the sup- 

 posed sometime arboreal habits of the Galli, based upon the 

 evidence of the development of the remiges, will have to 

 follow many more of its kind into the land of oblivion ; at 

 any rate it will have played a good part if only by serving to 

 stimulate a search after the real explanation. 



