SIAMESE CRESTED FIREBACK 119 



remaining upper parts. Mid-back black, coarsely barred with buffy white ; lower back, 

 rump and tail-coverts similar, but the barring disintegrates into a coarse mottling. 

 Scapulars, wing-coverts and secondaries black, strikingly barred with white, the centre 

 of the bars showing considerable black mottling. The exposed portions of the greater 

 coverts and secondaries show much greenish gloss. On the primaries the bars become 

 buffy or rufous-brown, and are much broken. Two central pairs of rectrices closely 

 resemble the secondaries, but with the eight or more bars much diffused with mottling. 

 Third pair of tail-feathers chestnut, with a great deal of black barring and mottling 

 on the inner webs ; the remaining rectrices and under tail-coverts clear chestnut. 

 Entire ventral surface reddish-chestnut, the breast almost monochrome, but with a 

 white marginal fringe appearing on the lower breast, and increasing in extent over 

 the remaining posterior ventral plumage. Upper mandible dark, lower chiefly yellowish 

 horn colour ; irides hazel brown ; facial skin, legs and feet scarlet ; claws whitish horn. 

 Spurs low, sharp scalules. Bill from nostril, 16 mm. ; wing, 223 ; tail, 202 ; tarsus, 81 ; 

 middle toe and claw, 46. 



The female diardi is interesting as exhibiting the same differentiation of pattern 

 in the tail as is shown by the males of Acomus and the other species of Lophnra. 



Juvenile Plumage. — Crown (lacking a crest), sides of head and back of neck 

 dark, smoky brown, merging into the mantle, which is rufous, slightly mottled with 

 dark. On the scapulars a black spot occurs, and on the mottled grey wing-coverts 

 this increases until the pale buff colour is confined to the tip and to several narrow 

 transverse bars. On the inner secondaries these become very distinct, each feather 

 showing six or more straight, narrow cross-bars on a black field. The tail-feathers 

 are chestnut, marked and barred with blackish. The ventral plumage is dull brown, 

 faintly freckled with whitish. The specialized fiery back is only faintly indicated at 

 this age : a slight golden fringe much freckled and dulled with black and white, while 

 the bronze-red rump is barely suggested by a rather mottled chestnut fringe. 



First Year Plumage. — The wing of the young male Fireback [Coloured Plate 

 XXXVI, fig. 4], when in half-way transition between juvenile and first-year plumage, 

 is exceedingly interesting. One such wing showed primaries Nos. 9 and 10 full grown, 

 but with the sheath still clinging to their bases as plain evidence of their delayed 

 growth. Primaries i to 6 inclusive were new, i to 3 full grown, while Nos. 4, 5 

 and 6 were new feathers in active growth, measuring respectively 149, 124, and 99 mm. 

 out of their sheaths. Nos. 7 and 8 were still unshed. 



It should be remembered that the wing-feathers of the adult male, both primaries 

 and secondaries, show no complex patterning. The former are brownish-black faintly 

 flecked with grey; the secondaries are all evenly and minutely vermiculated (chiefly 

 on the outer webs) with white. Keeping this in mind, such a wing as that which 

 we shall describe is most interesting and significant. The gradation of specialized 

 pattern revealed by the delayed growth of the outermost primaries, together with the 

 presence simultaneously of pure juvenile and typical adult feathers, gives us, upon 

 the surface of the single wing, a review of all the ontological pattern changes through 

 which the young bird passes as it gradually attains the adult state. 



