554 FEMALE ORGANS OF GENERATION. [cHAP.XXXVlll. 



mature ova than in ova at an early stage of development, as was 

 pointecTout by Bischoff, an observation which we can fully confirm. 

 They appear to be composed of a protein compound, with much 

 fatty matter. 



Germinal Vesicle. The germinal vesicle, or vesicle of Purkinje, 

 consists of a perfectly clear cell, filled with transparent contents, 

 but containing one dark spot, the germinal spot. 



From some observations of Kolliker and Bagge upon the de- 

 velopment of the ova of intestinal worms, it appears that the 

 germinal spot is the part of the ovum which is first formed ; but 

 it may be regarded as a fact, that the germinal vesicle precedes the 

 formation of the yolk and the zona pellucida. The immediate 

 formative organ of the ovum is the Graafian vesicle. 



As the ovum approaches maturity, it passes from the centre of 

 the Graafian follicle towards its peripheral portion, and becomes 

 imbedded in the membrana granulosa, which increases in thickness 

 until it entirely surrounds the ovum. At the same time, the zon 

 pellucida increases in thickness, and the germinal vesicle, which 

 was originally situated in the centre of the yolk, makes its way 

 towards the circumference. 



Parovarium. Diverging from the hilus of the ovary, may be seen 

 a few canals, which appear to be the remains of the Wolffian body, 

 an organ which reaches its maximum of development in intra 

 uterine life. These tubes have been termed the parovarium. 



Fallopian Tube. The Fallopian tube, or oviduct, is a fibro-muscul 

 canal, lined with ciliated epithelium, opening by one extremity 

 into the uterus and terminating in the other by a wide fimbriated 

 orifice, morsus diaboli, which opens into the cavity of the perito- 

 neum. Each Fallopian tube is usually, however, connected to t 

 corresponding ovary by one of its fimbrige. 



The Fallopian tube is invested with peritoneum, and at the fi 

 briated extremity, the serous membrane becomes continuous wit 

 its mucous lining. The muscular fibres of the Fallopian tube 

 are disposed in two layers; the external having a longitudinal 

 and the more internal a circular course. The contractile fibres are 

 mixed with much fibrous tissue. The contraction of the oviduct 

 has a vermicular character. The mucous membrane is disposed in 

 longitudinal folds, upon which lies a single layer of columnar epi- 

 thelium. These cells are ciliated, and by the vibration of the cilia, 

 a current is produced, the direction of which is from the ovaries 

 towards the uterus ; so that the transmission of the ovum into the 

 uterus would be favoured, while the passage of the spermatozoa 

 along the tube would be retarded. 



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