Handbook of field and general ornithology; a manual of the structure and classification of birds (1890) (14746826671)
Summary
Identifier: handbookoffieldg00coue (find matches)
Title: Handbook of field and general ornithology; a manual of the structure and classification of birds
Year: 1890 (1890s)
Authors: Coues, Elliott, 1842-1899
Subjects: Birds -- Collection and preservation Birds -- Classification Birds -- Anatomy
Publisher: London, Macmillan
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: Biodiversity Heritage Library
Text Appearing Before Image:
viduct to the ovary, there to accomplish impregnationof the ovarian ova, the fecund product then passing down by thesame avenue. All that relates to the mysteiies of generation—boththe structure and function of the reproductive organs, and thematuration of the product of conception, is properly Oulogij (Gr. C)ov,oon, an egg); though the term is vulgarly used to signify merely adescription of the chalky substance in which the egg of a bird is GENERAL ORNITHOLOGY PART II finally invested. The anatomy of the egg is Emhn/olof///. An egg,or ovum, is simply the product of conception up to the time thatproduct acquires an independent existence ; while still connectedwith the female tissue of the ovary, and before or after it amalgam-ates Avith the male element, it is an ovarian oviim; more or lessincompletely matured, it is an embryo or foetus—the former termbeing commonly applied to the unhatched young of birds. Theonly diiference between the egg of a viviparous mammal and -,C?)(C::>
Text Appearing After Image:
Fig. 103. — Urogenitalorgans of male embryo bird ;from Owen, after Mtiller. a,kidneys ; h, ureters ; c, Wolf-fian bodies; il, their ducts,to become sperm-ducts ; e,genital glands, to becometesticles ; /, adrenals. Pig. 104.—Urogenital organs offemale embryo bird; from Owen,after Miiller. a, kidneys ; h, Wolf-fian bodies ; o, genital gland, tobecome ovary ; tZ, adrenals ; e, ure-ters ; /, Wolffian ducts, to disap-pear ; (J, Miillerian ducts, to becomeoviducts. Fig. 105.—Urogenitalorgans of the domesticcock ; after Owen, a,testis ; h, epididymis ; c,sperm-duct or vas de-ferens ; d, adrenal; k,cloaca; x, kidney; y,ureter. that of an oviparous bird is in the albuminous and cretaceousenvelopes of the latter, and its speedy expulsion from the body ofthe female to be hatched outside, without anatomical connectionwith the mother after the hard shell is formed; whereas in mostmammals the ovum is retained in a dilated part of the Miillerianduct (uterus or womb) until it hatches ; but mamm