Indiiration and Atresia of the Cervix Uteri 685 



of the cervical canal. These instruments should be made very 

 strong. Introduced through the canal closed, they are to be 

 opened by means of a screw or other mechanism, and the cervical 

 walls thus forced apart. 



Since most of these instruments open to a greater extent at 

 the apex than at the base, they imitate the natural method for 

 bringing about the dilation. While some patterns of dilators 

 have their jaws open along parallel lines, those which are di- 

 vergent, so that thej' open wider at their apex than at their base, 

 are to be preferred. 



Some have suggested sponge-tents, in which a compressed 

 piece of .sponge is introduced into the narrow cervical canal, left 

 there to absorb fluids, thus to become greatly enlarged and 

 force the walls apart. Others have suggested rubber bags of 

 various forms, which may be introduced through the cervical 

 canal empt}' and then dilated by having warm water forced into 

 their interior. 



In our experience, however, it is best to rely upon the careful 

 manual or instrumental dilation. This should be accomplished 

 verj' gradually and with much care, since any violence may 

 cause serious injury to the parts. 



Induration and Atresia of the Cervix Uteri. 



In the cow, and more rarely in other domestic animals, there 

 occurs an induration of the cervix uteri, apparently the result of 

 some injury or disease which has established a chronic inflamma- 

 tion of the part and led to its thickening and becoming sclerotic, 

 with a consequent narrowing or even closure of the cervical 

 canal. In dealing with the anatomy of the cervix uteri, we 

 have already noted in ruminants, and especially in the cow, that 

 the cervix is usually highly developed and contains numerous 

 circular muscle fibers, commingled with a large amount of con- 

 nective ti.ssue, which gives to the part a preeminently rigid 

 character. 



This normal character of the cervix, with its .slow respon.se to 

 the dilating influence of labor, tends con.stantly to induce injuries 

 during parturition, which may later lead to a chronic inflamma- 

 tion and thickening of the part, to eventually end in induration 

 and a loss of dilatability. It is generally presumed to occur 

 chiefly in cows which have previously given birth, and suffered 



