MUSCULAR TISSUE OF THE UTERUS. 477 



that it is only with great difficulty that they can be isolated. 

 The fasciculi are again combined together by a large quantity 

 of nucleated connective tissue and a few elastic fibres. 



The fibre cells of the uterus, as a rule, are fusiform, and often 

 present very attenuated extremities ; in the pregnant condition, 

 however, (besides the formation of new cells,) the contractile 

 elements attain so great a development that their length, 

 instead of 0'045 of a millimeter, becomes O660 of a millimeter, 

 and their breadth, which was originally 0'009 0'014, increases 

 to 0-074. Many of the muscular fibres have shovel-like, flat- 

 tened, and dentated edges. The transverse section of the cells 

 presents a rounded, ovoid, three to five-angled outline cor- 

 responding to the several angles seen in surface views. 



The cell substance is only unclouded in the fresh condition, 

 and during the first two-thirds of pregnancy ; it is at this 

 period translucent, and allows the nucleus, which is never 

 absent, and the granules, which are also constantly present at 

 the two extremities, to be distinctly recognized * 



The nucleus, always single, is elliptical, fusiform, or rod- 

 shaped, and varies from 0-002 to 0-015 of a millimeter in length, 

 and from 0-001 to 0-003 of a millimeter in breadth,f (and these 

 measurements also become nearly doubled in pregnancy.) In 

 the greater number of cases it lies in the ventricose enlargement 

 commonly found near the centre of the cell, but is often also 

 excentric or attached to the walls. The brilliant granules 

 occurring in the nucleus are still a subject of controversy .J 



The measurements above given do not hold for the muscular 

 fibres of all the layers, but only for those which play an im- 

 portant part in the expulsion of the foetus. The superficial fibre 

 cells are shorter, more slender, and more cylindrical, like the 

 muscular cells of the innermost layer, the length of which only 

 amounts to 0*018 0'034 of a millimeter, and which do not 

 present any remarkable hypertrophy during pregnancy. 



The mucous membrane lining the interior of the uterus 



* Arnold, see this Manual, 1868, p. 192. 



t Frankenhauser, Die Nerven der Gebarmutter. Jena, 1867. 



I Hessling, Gewebelehre, 1866. Frankenhauser, loc. cit. Arnold, loc. cit. 



Kolliker, Zeitschrift fur wissenschqftliche Zoologie, Band i. 



