444 GROWTH AND STRUCTURE OF TAENIA SAGINATA. 



them serves for the reception of the lower end of both vagina and 

 uterus. About half-way up the wings are connected by a duct, which 

 runs across over the receptaculum seminis. That ovary, which lies 

 below the vagina, and is embraced by its curve, is always smaller 

 than its fellow, which is free to extend anteriorly, and reaches not 

 only beyond the vagina, but also beyond the vas deferens. 



As to their minute structure, both ovary and yolk-gland consist of 

 a system of blind tubules, which, as in the so-called " tubular glands," 

 are seated on a branched efferent duct. I have never been able to 

 observe the reticulated communication which Sommer describes 

 between the tubules, and must say the same with regard to the coils, 

 with branches running backwards, which Platner has described in the 

 ovary (his " yolk -gland "). In teased preparations with low power one 

 may indeed see appearances of this sort, but closer examination shows 

 that the apparent network is composed of tubes lying across one 

 another. The ends of the glandular tubules are not unfrequently 

 widened into acini borne on thin stalks. This is specially true in 

 regard to the ovaries, which thus acquire a somewhat less dense 

 texture, and a more transparent appearance. 



It is doubtful whether the bounding membrane of the tubules is 

 an independent skin, as in the testicular vesicles, or merely belongs 

 to the matrix. It is, at any rate, the only boundary of the glands. 

 The contents both of yolk-gland and ovary consist of cells about 0'007 

 mm. in size, with vesicular nuclei and distinct nucleoli. On the 

 whole, they resemble one another, but exhibit many differences on 

 closer inspection. 



The cells of the ovary (the primitive eggs) have a sharper contour, 

 and are provided with a thin, clear, protoplasmic envelope ; they have 

 also a larger nucleus (the germinal vesicle), whilst the cells of the 

 yolk exhibit an abundance of a finely granular enveloping mass, not 



unfrequently exceeding the above-mentioned 

 normal size. They are often very irregular 

 in form. Here and there the individual 

 cells are hardly distinguishable. They have 

 broken down and fused together into an 

 amorphous secretion, in which one can dis- 

 tinguish only a few flakes and nucleus-like 



Fia. 251. — Mehlis' body in structures, 

 connection with the various _, _l- i , ,i 



parts of the female productive The connection between these organs 

 organs, a. Efferent canal of the and the sliell-gland Can Only rarely be seen 



yolk -gland, b. Efferent canal .,, i- .• , t t i j.- 



of the ovary, o. Vagina and re- With any distinctness. Its demonstration IS 

 ceptacuium, d. Uterus. ( x 30.) the most difficult part of the anatomy. It is 



most easily seen in the neighbourhood of the yolk -gland, for its efferent 

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