550 



UTERUS AND ITS APPENDAGES. 



a common lens, the appearance of being 

 formed into bundles or laminae. 



The microscope, however, serves to resolve 

 this tissue into its true elements. When so 

 examined, the stronia is found to be composed 

 mainly of blood-vessels, to which a great part 

 of its strength and toughness is due, the in- 

 termediate spaces being filled up by a fibrous 

 structure not separable into bundles, like 

 ordinary connective tissue, and having no dis- 

 tinct fibrillar arrangement, its chief elements 

 being single white fibres of ordinary connective 

 tissue, numerous fusiform embryonic fibres, and 

 elliptical and round cells or granules, the whole 

 being coherent and strongly united together. 



3. The Graafian Vesicles. Folliculi ovarn, s. 

 Graafiani, s. Ovisacci. When the substance of 

 a healthy ovary is divided by a clean incision, 

 if the subject be not too advanced in life, the 

 section will be found to have included several 

 vesicles varying in diameter from 4"' down 

 to sacculi of microscopic minuteness. These 



Fig. 372. 



longitudinal section of adult ovary. {Ad Nat.) 



a, distal ; b, proximal end ; s, stroma ; g, Graafian 

 follicles of the ordinary size before enlargement; 

 h, stellate remains of follicles which have burst and 

 shrunk after discharging their ova. 



vesicles, familiarly known as the ova of De 

 Graaf, although the credit of antecedent ob- 

 servation is certainly due both to Vesalius * 

 and Fallopius f, are variously distributed 

 through the ovary according to the age of the 

 individual. In infants and young subjects, the 

 ovisacs are found only at the periphery of the 

 organ, where they form a thick rind, the inte- 

 rior of the ovary being occupied only by blood- 

 vessels and stroma. But after puberty the 

 division into a cortical and central part be- 

 comes less distinct, theovisacs becoming buried 

 deeper in the stroma, so that occasionally, in 

 making sections of the part, they are encoun- 

 tered as deep as the base of the organ. They 

 are always, however, most numerous near the 

 surface. 



The number of developed vesicles contained 

 in each ovary, and visible to the naked eye, 

 varies considerably in different subjects. Up 



* De Corporis humani Fabrica, lib. v. cap. xv. p. 

 459. 

 t Obs. Anat., Op. omnia, 1606, vol. i. p. 106. 



to a very recent date it appears to have been 

 assumed that their number was limited. They 

 were usually estimated at 12 to 20 in each ovary; 

 and it was generally supposed that, when these 

 were exhausted by child-bearing and miscar- 

 riage, the power of procreation of necessity 

 ceased. More recent and careful observation, 

 however, has shown that the number of vesi- 

 cles in each ovary amounts in healthy organs 

 to 30,50, 100, or even 200; whilst in very 

 young subjects their numbers exceed all power 

 of accurate computation. 



The vesicles are most easily displayed in 

 the adult ovary by making a perpendicular 

 section through the organ in the direction of 

 its longer axis. In this way the largest num- 

 ber will have been divided by one incision ; 

 and such a section, as in Jig. 372., will often suf- 

 fice to exhibit 8 to 12 vesicles of different 

 sizes. On submitting the section, however, 

 to the microscope, others of a smaller size, 

 which had previously escaped attention, will 

 be brought into view ; and in continuing the 

 incisions in various directions, fresh vesicles 

 will be laid open of various sizes and in dif- 

 ferent stages of development. If the ovary 

 of an infant be selected for observation, the 

 organ should previously have been hardened 

 by maceration for several days in spirit. A 

 clean section is thus easily obtained by a sharp 

 knife; and if this be examined by a 1-inch ob- 

 ject glass, the little spherical ova, coagulated 

 by the action of the spirit, will be readily seen, 

 each one lying in its proper ovisac, by which it 

 is immediately surrounded, and the whole so 

 closely set and so numerous that a single sec- 

 tion suffices to display several hundred of 

 them at one view (fig- 373.). 



Fig. 373. 



Section of part of the ovary of an infant, aged 20 

 months. The central portion consists of stroma 

 and blood-vessels only. The lighter peripheral part 

 is composed entirely of close-set ovisacs, containing 

 ova of various sizes. (Ad Nat. x 16 diam.') 



The Graafian follicle, when not subjected to 

 pressure from surrounding parts, or from ad- 

 jacent vesicles, is spherical or oval in form, (Jig. 

 371. DD, and Jig. 372. g) and consists of cer- 

 tain tunics and contents. The number and 

 composition of its coats have been variously 

 described by recent observers ; and upon this 

 subject a difference of views would be of com- 

 paratively little importance, if upon a right 

 solution of this question did not depend the 

 clear comprehension of those changes which 

 occur in the Graafian follicle during preg- 



