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anatomy of the ileum and caecum and with it I do not propose to 

 deal. 



The point at issue is the superior boundary of the caecum from 

 its external aspect, or in other words the localisation of the ileo-caecal 

 valve upon the outer surface of the caecum. 



In this connection Treves (1) speaks of the superior boundary 

 of the caecum as being "at the level of the lower border of the ileum". 



Stkuthers (2) however seems to be more accurate when he says "In 

 taking the length of the caecum the ileum is not a reliable guide; 

 if taken from the lower edge of the ileum the measurement falls short, 

 especially when as often happens, the last stage of the ileum is direc- 

 ted very obliquely upwards. The upper end of the ileum would be 

 a less variable point than the lower edge, but it goes about V2 an 

 inch above the level of the orifice. The measurements should be 

 taken from the middle of the anterior and posterior fraenal furrows.'' 



These furrows are not always marked externally, as my series of 

 photographs of 100 caeca show. Consequently, good though this 

 method may be it is a somewhat unreliable one. 



With the exception of Tuffier I have been unable to find any other 

 author who has touched upon this question of the superior external 

 boundary of the caecum — a point which I hold to be of some im- 

 portance, corresponding as it does to the position of the ileo-caecal 

 valve. 



Treves' statement just quoted, I regard as more or less erroneous» 

 and I think I succeeded in proving that such is the case by a series 

 of plaster of Paris casts made from the interior of the viscus. Measure- 

 ments were first made of the caecum according to Treves' method, 

 thus, an imaginary line was drawn across the large intestine at the 

 level of the lower border of the ileum. This line was then measured 

 and should give, according to Treves, the breadth of the caecum. 

 The length being everything below this point. 



To test these measurements casts were made in 45 cases. The 

 cast, of course, accurately reproduced the site of the ileo-caecal valve. 

 The cast was then imeasured and photographed simultaneously, and 

 I may mention that in order to reduce error to a minimum both 

 measurements were made under the same conditions that is with the 

 parts distended, — in the one case by water and in the other by 

 plaster of Paris. 



On contrasting the two methods it was found that the measure- 

 ments seldom or never coincided. As the casts can hardly be erroneous 



