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THE


Avicultural Magazine,


BEING THE JOURNAL OF

THE AVICULTURAL SOCIETY

FOR THE STUDY OF

FOREIGN & BRITISH BIRDS

IN FREEDOM & CAPTIVITY.



Third Series. —Yol. X.—No. 3.— All rights reserved. JANUARY, 1919.



FURTHER NOTES ON GROWTH OF

MARKINGS AND COLOUR.


j


Bv Arthur G. Butler, Ph.D.


Spots and ocellated markings in birds have obviously not been

always developed in the same way ; thus, although the ocelli in the

upper tail-coverts of Peacocks (as Darwin points out in Chapter XIY,

of his 4 Descent of Man,’ pp. 655-661) have originated in twin spots,

separate in Polyplectron chinquis , hut partly confluent in P. malar -

cense, yet the remarkable ball and socket markings on the Argus

Pheasant are shown to have originated in dark stripes or rows of

spots, which run obliquely down the outer side of the shaft to the

ocelli. From Darwin's illustration on pp. 663, 664, 665 and 668, I

should judge that the feathers were originally longitudinally striped,

that the stripes were broken up into spots as in Figs. 58 and 59, and

with the development of the ocelloid markings decreased in size and

finally reunited.*


Ocelli in lepidopterous insects are, I believe, more often than

not, developed from parallel undulated lines or stripes ; in the cowrie¬

like markings on the wings of Brahvuea Swanzii and its close allies

every gradation is shown between the perfect shell-like and accurately


* In Fig. 60 the inner rows of spots are seen to have already partly merged into

stripes.



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