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THE


Avicultukal Magazine,


BEING THE JOURNAL OF

THE AVICULTURAL SOCIETY

FOR THE STUDY OF

FOREIGN & BRITISH BIRDS

IN FREEDOM & CAPTIVITY.



Third, Series. — Yol. X.—No. 2 . —All rights reserved. DECEMBER, 1918.


THE EMBRYONIC LIFE OF THE OSTRICH.


By M. Aubry.


Translated by the Editor from the ‘Revue Framjaise d’Ornithologie.’


Natural incubation being often very difficult and restricted in

scope, artificial methods have assumed a growing importance. We

have had to employ only the latter methods at the Ostrich farm at

Mekn6s—in the end at least. The study of the advantages and draw¬

backs of each of these methods will appear in the body of this work,

which has the single aim of explaining the most remarkable features

noticed in the course of the embryonic life of the Ostrich.


Incubation lasts from forty to forty-five days ; it varies with

the strength of the chick, and lasts from forty-four to forty-five days

in cold weather, which causes many failures. One need not attach

importance to the appearance of the shell; it is enough for it to be

normal with the pores permeable to the air. The shadow-test gives

no guide.



The Germ at the Beginning of Incubation.


As in fresh eggs, the discus proligerus is alone visible, so that

the early shadow in the egg of the Ostrich does not permit one to

separate at once clear from fertile eggs. It is at this period that the

embryos readily die ; they already show bulging of the head with


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