AQUIJSrTOCTJBITALISM EST THE BIBD S WING. 



243 



more) rows of minor coverts are all represented, but, as yet, tbe 

 wing is undoubtedly eutaxic, tbougli soon after this stage it 

 becomes diastataxic. A foresbadowing of this is plainly visible 

 at the stage under discussion. A reference to Plate 15. fig. 2 

 shows that the remiges 1-4 have already begun to move 

 backwards through a small arc of a circle, the movement having 

 been greatest at the distal end of the row, whilst the proximal 

 end, represented by the 4th remex, has as yet scarcely moved at 

 all. It may be expressed thus— ", the black line repre- 

 senting the original and the dotted line the new position. The 

 disturbance is much more obvious in the row of papillae imme- 

 diately above the remiges — the rudimentary major coverts 1-5. 

 These have become distinctly separated from the rest of the row 

 proximad of this point. The disturbance of the rows preaxial to 

 this of the major coverts is barely perceptible. There is yet no 

 intercalary row. I have no stage between this and that of the 

 nestling (woodcut, fig. 2). 



Fig. 2. 





^r^fd C. 



Eight wing, dorsal aspect, of nestHng Lomvia troile, to show the diastataxic 

 arrangement of the coverts. 



The wings of the Pigeon {Columba domestica), Duck {Alius 

 hoscas), and Owl (Syrnimn aluco) are selected as examples 

 of typical embryonic diastataxic wings. In earlier stages of 



18* 



