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FRANKLIN PARADISE JOHNSON 



development of villi and jihmds as compared with the rectum, 

 descending and ascending colons. However, this retardation is 

 soon overcome by an increased rate in growth, and then con- 

 ditions found in all parts of the large intestine are quite similar. 

 As a matter of convenience and simplicity, the development of 

 the transverse colon has been described most completely in the 

 remainder of this article, and other portions of the large intes- 

 tine are described, as far as is possible, from a comparative 

 point of view with respect to it. 



Fig. 3 ('ross section of the transverse colon of a liiunan embryo of ()5 mm. 

 X 60. 



The transverse colon of an embryo of 65 mm. differs con- 

 siderably from that of the embryo just described. The epithe- 

 lial tube is circular in section and measures 0.54 mm. in diameter. 

 In transverse section (fig. 3) eighteen to twenty-three projec- 

 tions are seen extending into the lumen. When modelled these 

 projections are seen to be longitudinal folds and villi as shown 

 in figure 20. The villi are everywhere arranged in longitudinal 



