Introduction: Variation. 
63 
The moult. - In the tempemte and cold regions of the northern 
it is generally admitted that a complete moult takes place m budsjn^ ^ 
after the breeding season; many species moult again m spiin„, 
time in summer The principal time for moulting in 
and Talaut seems to be from July to December 1“ Z snrinl 
undergo a complete post-nuptial moult. It is questionable whether “jns of a sp » 
moult can be found; on the other hand some species may be found i^uUm 
during most months of the year. For instance specimens in he Dierfen 
Museum of Ileteractitis brevipes are moulting in January, Apii , J, 8 ’ 
Noreinher; of AcUtis hypoUueos in January, March, y, ovem ei. 
Some of the Waders, autumn visitors from the North to 
pot^eopl, BeteeaoUtl,, seem to “^LTr Tn Siting is puZe^^^ 
“e Bi:S^S:nbtLT^— );a™ong wU the transition 
male dress can be particularly well observed. The charactens m — -b 
gular stripe of the Celebesiaii species makes its there is a 
of the plumage is developed without (c 15377) in almost 
specimen of Hemiotmm talauteum lu t ^ 
complete adult dress except on the foie . ■ forehead and most 
same species (C 13847) has the plumage of hydu 
of the crown, but the young ““ ™dj drL does not take place in 
that the transition from the young to the adu not necessarily 
perfect phylogenetic order; that is, the adult c “““ sequeiioe as 
developed in the young male bird in exa 'l the race (see, 
that in which they were acquired in the ev 
also, immature male, pp. 469, 471). r-ompoiis 
Besides their feathers some birds are known to s e c Pelican of 
appendages or coverings on their bills; for instance, e w 
America has a horny knob on the culmen moults the 
which falls off when that period is ovei, and t /\T„wtnn D B, 
hoiny sheath of its bill and the outgrowths over '^e J-^d pTafos at th': 
pp. 599, 600). It is possible that a s.mi ar takes place, 
base of the bill of the Celebesian Horn , thoiinh this 
It is beheved by the natives to add one rib-plate ““ 5 ^ 
notion is certainly ivrong, it is possible that a shedding of the plate 
observed. 
autnpe of coloration without a moult. 7, tfe tt “itluy 
(1897, April) Dr. Chadbourne has finnmhed 
conclusive evidence *ot a c ““‘ Jtribution of the pigments already present 
feather, this ““f ^J!;Vobset“were made on the male Bobolink, 
in the shaft and bal . h principle is 
Dolichonyx oryzivorus (L.), but tnei 
