18S7.] OF THE WINGS OF BIRDS. 349 



feathers, in their undisturbed primitive conditions. Sundevall men- 

 tions that there are generally one or two extra major coverts connected 

 with the cubital series, of which the feather I in his figures (the 

 median covert here under consideration) is one. The other he does 

 not mention (S. p. 414, par. 2). Really there are no extra coverts 

 at all, unless the fifth cubital coverts in the aquincubital condition 

 of the wing are so considered. In the Duck (Plate XXXII. fig. 8) 

 it is seen that the larger feather (1"), which at first sight appears to 

 represent the major covert, is really tlie median covert in front of the 

 remex in the undisturbed quincunx series; the little feather (!') under- 

 neath being the real major covert. In this wing the two feathers 

 have not become so closely attached to the first metacarpal as is 

 the case in some other birds, example the Golden Eagle, Barn-Owl, 

 &c. (Plate XXXII. fig. (5). Here the relations are more apparent ; 

 the major covert is small and rudimentary, but bears the same 

 relation the other major coverts do. The median covert is a fairly 

 large feather, which crosses the metacarpals at a considerable angle. 

 In the Duck the median covert of metacarpal 2 is suppressed, in the 

 Eagle it is present (2", fig. C). The Grebe, with seven metacarpals, 

 shows similar modifications at the wrist-joint (Plate XXXII. fig. 7). 

 In many birds {e.g. Passerines) the major covert altogether disappears, 

 the median covert is large, and takes its place, lying across the 

 metacarpals at a considerable angle, and causing the suppression of 

 the next one or two mediae (Plate XXXII. fig. 9). 



The remaining feather-tracts undergo modifications in different 

 groups, which are generally of more or less minor importance. The 

 axillars and humerals vary in their development in different groups, in 

 the Passerines disappearing almost absolutely, in all probability in 

 connection with the relative shortness of the humerus. The marginals 

 in many birds of this group are much elongated on the ventral side 

 and cover the patagiuni. 



When the wing is folded these feathers (often with the last two or 

 three major cubital coverts) present much the appearance of the 

 axillars in some birds. They have often been erroneously so described, 

 whereas they have nothing whatever to do with them, the true 

 axillars being represented by but a few semiplumes at most. 



The modifications of the overlap of the dorsal cubital median and 

 minor coverts have recently been very fully worked out by Goodchild 

 (P. Z. S. 1886, pp. 184-203). These' feathers are' termed by 

 Goodchild the " median cubital coverts ;" but it is much better to 

 confine the term " median coverts " to the row following the majores, 

 and call the others " minor coverts." Goodchild's terms " sup- 

 plementary row of median coverts " or " upper wing-coverts " and 

 "posterior row of median coverts" are unnatural, because part of 

 his supplementary row in the majority of cases belongs to the 

 t. mediae, and the greater and proximal part of his posterior row to 

 the same, whereas the distal part belongs to the first row of minores 

 (c/. his fig. 1, p. 186, P. Z. S. he. cit.). His supplementary row 

 generally means the distal t. mediae proper, and sometimes includes 

 some of the feathers of the next two or three rows on the wrist, 



Prog. Zool. Soc— 1887, No. XXIV. 24 



