. A manual of zoology. Zoology. A n Fig. 93.—Egg of ^'ms (/(nckiiis lUiring fecundation. (After Fol.) ,1, entrance of the spermatozoon; J5, the s,termatozoon has entered : the yolk-membrane has formed. this abnormal fertilization. One, though by uo means the only one, is the formation of the yolk-membrane, an impermeable envelope which is suddenly secreted from the surface of the egg, as soon as the spermatozoon has accomplished the impregnation. Within the yolk-membrane the body of the egg contracts into a smaller volume by discharging smne of the more fluid constituents, so that betwee
. A manual of zoology. Zoology. A n Fig. 93.—Egg of ^'ms (/(nckiiis lUiring fecundation. (After Fol.) ,1, entrance of the spermatozoon; J5, the s,termatozoon has entered : the yolk-membrane has formed. this abnormal fertilization. One, though by uo means the only one, is the formation of the yolk-membrane, an impermeable envelope which is suddenly secreted from the surface of the egg, as soon as the spermatozoon has accomplished the impregnation. Within the yolk-membrane the body of the egg contracts into a smaller volume by discharging smne of the more fluid constituents, so that between the yolk-memliranc and the surface of the egg a cavitv is formed easily recognized in smaller fertilized eggs (fig. '%\, B). In the largo yolk-laden eggs of many insects and vertebrates several si)ermatozoa may normally enter. But this does not alter the conception. 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 Hertwig, Richard, 1850-1937; Kingsley, J. S. (John Sterling), 1854-1929. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1902
