THE TJTEKUS. 283 



of the membrane in health, is grayish, viscid, and feebly 

 alkaline. The tubes themselves have exceedingly thin, struct- 

 ureless walls, and are lined with cylindrical ciliated epithelial 

 cells. These cells have been accurately described by Lott, 

 who observed ciliary movement, as far down as their blind ex- 

 tremities, in some of the mammalia, the movement always 

 being toward the openings. 1 



The changes which the mucous membrane of the body of 

 the uterus undergoes during menstruation are remarkable. 

 Under ordinary conditions, its thickness is from -^ to -^ of 

 an inch ; but it measures, during the menstrual period, from 

 J- to J of an inch. 



In the cervix, the mucous membrane is paler, firmer, and 

 thicker than over the body of the uterus, and presents a dis- 

 tinct line of demarkation. It is here more loosely attached 

 to the subjacent tissue, and the anterior and posterior surfaces 

 of the neck present an appearance of folds radiating from 

 the median line, forming what has been called the arbor vitee 

 uteri, or plicse palmatse. These so-called folds are supposed 

 by some anatomists to be formed by rows of large, papillary 

 elevations of the membrane. Throughout the entire cer- 

 vical membrane, are numerous mucous glands, and, in addi- 

 tion, in the lower portion, are a few rounded, semitransparent, 

 closed follicles, called the ovules of Naboth, which are prob- 

 ably cystic enlargements of obstructed follicles. The upper 

 half of the cervical membrane is smooth, but the lower half 

 presents numerous villi. 



According to the recent researches of Lott, who has elabo- 

 rately investigated this subject and reviewed the opinions of 

 previous writers, the epithelium of the cervix presents great 

 variations in its character in different individuals. Before 

 the time of puberty, Lott is of the opinion that the entire 

 membrane of the cervix is covered with ciliated epithelium. 

 After puberty, however, the epithelium of the lower portion 



1 LOTT, Ueber das Flimmerepithel der Uterindrusen, in ROLLETT, Untersttehun- 

 gen, Leipzig, 1871, Zweites Heft, S. 250, et seq. 



