ME. E. DEGEN ON ECDYSIS. 



375 



sequence for renewal, as do the flight-feathers themselves, with the same constant 

 accuracy of recurrence in the species. As such, then, we have the astonishing fact 

 standing, that they moult (as may be seen from the drawing) m an op2)Osite direction 

 to the metacarpo-digital remiges. This is in no way an isolated occurrence, but a 

 condition which one finds twice repeated on the cubitus, and which, as I believe I am 

 justified in regarding, affords us the key to the original, if not pentadactyle, at least 

 tetradactyle feathering of some ancestral type of birds. 



D. Extract from and Remarks on the Table of Percentages for the Deficiency 



in the Poiver of Flight. 



When consulting the foregoing Table (III.)) it will be noticed that for both the lowest 

 and the highest percentages the figures are distributed fairly equally without having 

 any direct bearing upon either stage of moult, age, or sex of the individual. Thus we 

 get minima and maxima at all times during the changes. 



The lowest figures we get are as follows : — 



Left side . 

 Rigbt side 



Metacarpo-digitals . 

 . 2-1 (26) 

 . 2-9 (8) 



Cubitals. 

 •4 (21) 

 •2 (8) 



Totals for left side. 

 2-2 (8) 



Totals for right side. 

 3-1 (25) 



Grand total. 

 3-0 (25) 



The highest figures thus received are : — 



Metacarpo-digitals. 

 Left side .... 2-JI.-2 (14) 

 Right side .... 23-2 (4) 



Cubitals. 

 22-9 (12) 

 20-8 (16 & 17) 



Totals for left side. 

 23-8 (10) 



Totals for right side. 

 17-1 (4) 



Grand total. 

 20-1 (10) 



(The figures within the brackets indicate the number of the specimen.) 



It will be seen that, while the greatest amount of feather-loss incurred at any time 

 during the moult occurs on the hand-portion of specimen No. 14 with 24'2 per cent., 

 the cubital portion is only slightly behind this with 22-9 per cent., shown in^specimen 

 No. 12. 



For the totals, the highest one obtained is in the case of the left-side wing with 

 23'8 per cent., as against one of only 17'1 on the other side. 



An analysis for the different portions of the two wings, however, gives the general 



