Carpenter's principles of human physiology . M AND ITS DEVELOPMENT. 875 since /i represents a micromillhnetre or 0-0000032809 of an inch, 200 /x wouldequal -00065618, or about l-524th of an inch;, and is contained within a capsuletermed the Graafian follicle or ovisac* In a large Graafian follicle we may dis-tinguish a connective tissue investing membrane, which is composed of two layers,the tunica Jibrosa(g, Fig. 311), and the tunica propria folliculi (h) ; the latter islined on its internal surface by several layers of cells, of which the nearest to thetunica propria are columnar, whilst the
Carpenter's principles of human physiology . M AND ITS DEVELOPMENT. 875 since /i represents a micromillhnetre or 0-0000032809 of an inch, 200 /x wouldequal -00065618, or about l-524th of an inch;, and is contained within a capsuletermed the Graafian follicle or ovisac* In a large Graafian follicle we may dis-tinguish a connective tissue investing membrane, which is composed of two layers,the tunica Jibrosa(g, Fig. 311), and the tunica propria folliculi (h) ; the latter islined on its internal surface by several layers of cells, of which the nearest to thetunica propria are columnar, whilst the deeper ones are transparent and polyhe-dral (i), constituting the epithelium of the follicle, or membrana granulosa. Themembrana granulosa is collected round each ovum into a disk-like investmenttermed the discus proligerus (e, Fig. 311), and the remainder of the follicularcavity contains a clear fluid, the liquor folliculi. The earliest rudiment of everyovum consists of a simple cell with soft granular protoplasm unenclosed by a Fig. A, primordial egg of Man, from an eight months fetus; B, primordial egg of Rabbit; C, primor-dial follicle of a Pigeon; D, a somewhat older follicle from a Pigeon, showing commencing formationof secondary yolk ; _E, blind end of the ovary of an Ascaris nigro-venosa, showing germinal vesicle,germinal spot, and, in some instances, a SchrSns granule in a diffuse mass of protoplasm; F, egg ofAsearis nig. from about the middle of the ovary. &, an Ovum from the Graafian Follicle of a feabbit. a, epithelium of the ovum, part of the discusproligerus ; b, radially striated zona pellucida; c, germinal vesicle ; d, germinal spot; e, yolk. membrane, a nucleus and a nucleolus. The protoplasm of the primordial cellis termed the formative or principal yolk, since it alone undergoes segmentationand development. The nucleus is termed the germinal vesicle (Vesiculagerminativa) (c, Fig. 312 ; v g, Fig. 313), and the nucleolus, the germinal spot(Macula germina
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectphysiology, bookyear1
