. A text-book of agricultural zoology. Zoology, Economic. 344 SAUROPSIDA (birds). Fallopian tube in the female ; this single ovary is that of the left side. I have sometimes in the fowl found the right ovary more or less developed. The oviduct is a long tortuous tube in which the ovum receives first the " white " or albuminous cover- ing of the yolk. Towards the end of the egg-tube dilatations appear: in these the eggs receive the shell, which consists of carbonate of lime. A deficiency of this in the bird's system results in so-called " soft ; The egg is then passed i
. A text-book of agricultural zoology. Zoology, Economic. 344 SAUROPSIDA (birds). Fallopian tube in the female ; this single ovary is that of the left side. I have sometimes in the fowl found the right ovary more or less developed. The oviduct is a long tortuous tube in which the ovum receives first the " white " or albuminous cover- ing of the yolk. Towards the end of the egg-tube dilatations appear: in these the eggs receive the shell, which consists of carbonate of lime. A deficiency of this in the bird's system results in so-called " soft ; The egg is then passed into. Fia. 180.—Ovary or Bikd. a, c, c, Ova in various stages of development; 6, streak without vessels indicating the point where the vesinle is about to rupture to allow ova to escape; d, ruptured vesicle; e, very small ovrnn showing cicatricula. (Chauveau.) the cloaca, and so out of the vent. The eggs of birds are hatched by incubation. The young are provided with a curious calcareous knob on the upper mandible, by means of which they crack a hole in the eggshell when ready to escape. Some can feed as soon as they have escaped from the eggshell^—precocious young; others have to be fed by the parents—nestlings. Birds are found in all climates, and may be residents, migrants, or Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Theobald, Frederick Vincent, 1868-1930. Edinburgh and London, W. Blackwood and sons
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1899
