4 FRANKLIN PARADISi: JOHNSON 



upper he calls the "pars ampullaris recti;" the lower, ''the pars 

 analis recti. " He says : 



Zu dieser wichtigen Anderung im Verhalten des Bauchfelles kommen 

 noch zwei Punkte in der Structur der Darmwand selbst, welche dem 

 untersten Darmstiick eine besondere SteHung anweisen, erstens die 

 betrachliche Verstarkung der Muskulatur unci zweitens die Neuord- 

 nung der Langsfaserschichte (Aufhoren der Tanien), Dieses Ver- 

 halten der Muskulatur ordnet das Rektum in die Reihe der Blasenbe- 

 halter ein, als Kotblase (Waldeyer), eine Annahme, welche durch haufig 

 zu beobachtende spindelformig Erweiterung des Darmrohres (Pars 

 ampullaris recti) (Pars pelvina, Waldeyer) gestiitzt wird. Dieser erste 

 Teil des Mastdarmes reicht aber niemals bis zur Afteroffnung hin, 

 sondern man findet das letzte Stiick immer, in gleicher Weise leer and 

 zusammengezogen, so dass man dieselbe als zweiten Teil des Mast- 

 darmes (als Pars analis recti) (Canalis analis, Symington) von der Pars 

 ampullaris zu trennen hat. 



In a paper regarding this subject, Paterson ('08) writes: "The 

 superior rectal valve, though variable in its form, is, in my opinion 

 so generally present that it may be looked upon as the true 

 junction of the pelvic colon and the rectum." 



Symington ('12) believes with Paterson that the superior 

 rectal valve is a more reliable guide to the colo-rectal junction 

 than the termination of the mesocolon, as this latter ends so grad- 

 ually: "There is no reliable bony landmark serving as a guide to 

 the colo-rectal junction, since while the empty and contracted 

 rectum usually starts opposite the third sacral vertebra, when the 

 rectum is distended this junction may rise as high or even higher 

 than the sacral promontory. " 



Of the modern text-books of anatomy, Sobotta-McMurrich is 

 the only one of those I have examined which still follows the 

 description of Sanson, that is, considers three divisions of the 

 rectum, the first of which begins at the sacral promontory. 

 Cunningham regards as the rectum only that part of the digestive 

 tube which lies between the third sacral vertebra and the pelvic 

 floor. The 'anal canal' is treated separately. Other authors 

 speak of two parts which lie between the third sacral vertebra or 

 termination of the mesocolon, the pelvic floor or diaphragm, and 

 the anus. The terminology, however, differs considerably. Thus 

 the ampulla is considered as the lower part of the first portion of 



