376 Mli. E. DEGEN ON ECDTSIS. 



result of iin even lialance for the specimens as a whole, as may be seen by the following 



figures : — 



Higher "/« losses. 



Left side. Right side. Ecjii;il "jo loss. Total. 



Metacarpo-digitals .... 8 specimens. 10 specimens. 9 specimens. 27 specimens. 



Cubitals 10 „ 10 „ '7 „ 27 „ 



Composite wing 11 „ 12 „ 4 „ 27 ., 



Perfect symmetry is present only in four specimens ; these are Nos. 4, 14, 22, and 25. 

 For greatest differences of asymmetry amongst these specimens the numbers are dis- 

 tributed as follows : — 



For the metacar])o-digitals, two out of ten specimens, namely, one each (for each 

 side of the wing). These are Nos. 9 and 24. 



For the cuhitals, one out of 15 (for the left side). This is No. 10. 



These differences get considerably levelled in their aggregates, as may be seen from 

 the totals obtained between the left and the right wing of Nos. 8 and 10, which two 

 specimens show the amount of this difference to be one of 7 per cent, for each. 



Finally, as indicated in the column of percentages of the total feather-loss for 

 both wings (see grand totals), this does not exceed \ of all the flight-feathers, as 

 specimen No. 10 shows, with the highest total of all, viz. 20T per cent. 



E. The Wing-coverts. Tectrices primse serii s. majores. 

 1. Superiores. 



The upper major coverts are usually the most prominent ones of the series which 

 accompany the flight-feathers, and to which they are more closely related than are 

 any of the remaining series. They also resemble flight-feathers entirely, both in 

 texture and development. When fully developed, their length on the manus is about 

 one-third part of each flight-feather in this species. 



On the cubital portion these coverts are proportionately longer, covering about 

 one-half of their respective remiges. But whilst the latter maintain a nearly uniform 

 length as far as remex VII. , from whence to the last or remex X. they rapidly decrease 

 in length, their upper major coverts, on the contrary, slightly increase in length in 

 the same direction, i. e. towards the upper arm. 



In the flexion of the wing known as the carpal joint, the first covert belonging to 

 the hand and the first one belonging to the cubital portion, which are directly approxi- 

 mated here, are of nearly equal lengths, as are also their respective flight- feathers. 



Metacarpo-digital 2^ortion. — The order in which the dorsal major coverts make their 

 appearance on the manus is precisely the same as that of the remiges, being one of 

 perfect synchronism both for growth as well as for the respective sequence of renewal. 

 I have never found any deviation from this principle in the normally developed 



