18S7.] OF THE WINGS OF BUIDS. 345 



The remainino; feathers of the wing are the coverts; thev are best 

 understoml if described frnin the posterior mariiin of the vvina;. 



Oil tlie dorsal side the row of feathers (Plate XXX. fij:. a, n) 

 Ivinj;; next the remises are the tuctrices majorcs, being quite definitely 

 related to the reinigeal quills, and lying close pressed upon their 

 bases. Each remex is serial with the covert proximal to it, the 

 cubital coverts crossing over tlie bases of the rfniiges, the meta- 

 car[)al coverts lying parallel and pressed upon two contiguous re- 

 miges (c/l Plate XXXI. figs, b and c). There is a well-developed 

 covert to every metacarpal exeeut tiie first, which possesses only a 

 very small and vestiu;ial one, 1', vvhieh is completely hidden by a 

 median covert, 1" (Plate XXXII. fig. 8), which in many birds func- 

 tionally replaces it, the t. ma/or disap[)e.iring. 



On the ventral surface of the wing is a row of featliers (Plate XXX. 

 fig. b, «), bearing the same relations to the reniiges as those just 

 described ; these are the (ectrices majores of tlie lower surface (e/'. 

 Plate XXX. fig. 6, and Plate XXXI. fig. b). If fig. b, Plate XXX 11., 

 be examined, which shows the relations of the above feathers in 

 section, starting at thf tip of the wing tiie remicle, or jiredigiial 2 

 (R'), is seen to have proximal to it a dorsal and ventral covert, term- 

 ing a group of three. The next remex is similar, and so to the 

 1st metacarpal, whose dorsal covert is very small and rudimentary. 

 These relations show that the remicle is a small metacarpo-digital 

 whicli has probably not been differentiated into a flight-feather. The 

 cubitals show the same arrangement except the fiftli group, where 

 there are a pair of coverts, but no remex ; this condition is termed 

 aquincubital, and is later described more fully. 



On the dorsal surface the next row of feathers to the t. majores 

 are the median coverts (Plate XXX. fig. a, /3), or tectrices medicp, 

 arranged serially with the other groups. On the cubitus they lie 

 with a reversed overlap to the remiges and t. majores ; those, how- 

 ever, which lie most proximal are unreversed (S. p. 4\f>, footnote, 

 and Goodchild, P. Z. S. 1880, p. 191). Those on the manus lie 

 unreversed, and generally the median covert of the 2nd metacarpal 

 is wanting (c/". Plate XXXII. fij:. 8). On the ventral surface of the 

 wing, the next row of feathers (Plate XXX. fig. b, /3) bears similar 

 relations ; they are the tectrices media of the lower surface, and 

 always lie with reversed overlap to the remiges and t. majores (S. 

 p. 491). The distal tour or five are generally deficient on the manus 

 in the Duck (Plate XXXI. fig. b). In many birds they are nearly 

 all suppressed on the manus. 



The tectrices majores and mediEc on the ventral surface have at 

 first sight an anomalous position. Being on the ventral side of the 

 adult wing, one would expect the backs of the feathers to look 

 ventralwards, whereas they look dorsalwards just as do the remiges. 

 This is pointed out by Sundevall (S. p. 419), who, however, gives au 

 erroneous explanation, saving they are aftershafts developed at the 

 ex >ense of the true feather-shaft; a more probable explanation is 

 discussed later. 



The feathers so far described are seated in the wing-membrane, 



