132 DR. E. KLEIN. 



the crypts of Lieberkiihn of the small intestine with those of the 

 large intestine — of course in the same animal — it will be found 

 as a rule that the epithelial cells are longer in the latter than in 

 the former locality. Besides these permanent differences in size 

 of the epithelial cells of the crypts, there are others that are only 

 temporary, being dependent on the state of distension of the 

 crypt. Thus we notice in the large intestine in some places a 

 considerable difference in the size of adjoining crypts, and also 

 in the length of the epithelial cells lining them. For example, 

 I find in an horizontal section through large intestine of pig as 

 the mean of several measurements :— 



a. Diameter of crypt .... 0"067 mm. to O'DIS mm. 



b. Diameter of lumen .... 0'021 mm. to O'OIS mm. 



In a the length of the epithelial cells is about 0'022 mm. ; in 

 h it is about 0'015 mm. ; the greatest length of the epithelial 

 cells in general is here 0"027 mm. ; the smallest 0*01 mm. 



Now, the longest epithelial cells are not always found in the 

 largest nor the shortest cells in the smallest crypts, nor do we 

 find the length of the lining epithelial cells the same throughout 

 one and the same crypt. Thus, for instance, I find in a good 

 many places the length of the epithelial cells in the middle part 

 only half or two thirds of those lining the mouth and the 

 fundus of the same crypt. Passingly I may mention that in 

 the short epithelial cells the nucleus is always spherical. 



As a rule it may be taken as correct that, catcris panhuSy the 

 length of the epithelial cells varies according to the state of 

 distension of the crypt, or according to the amount of mucous 

 secretion present in the cavity of the crypt. Thus I measure in 

 some crypts, distended by mucous secretion, a lumen of 0'054 

 mm., the whole transverse diameter being only 0"071 mm. ; that 

 is to say, the length of the lining epithelial cells is only O'Oll 

 mm. In another place I find a crypt with a lumen of only 

 0*01 mm. in diameter, whereas the whole transverse diameter 

 amounts to 0*067 mm.; this gives 0-027 mm. as the length of 

 the epithelial cells. Such examples I could multiply ad libitum. 



It seems to me probable that also the state of contraction of 

 the mucosa, i. e. the tissue surrounding the crypts, has something 

 to do with the length of the epithelial cells lining them; 

 the contracted state of the crypts, if I may be allowed to use 

 such a term to indicate those tubes that have a thick epithelial 

 lining and a small lumen, seems to point in that direction. 

 Whether the epithelial cells themselves have the power to actively 



^ The above measurements refer only to horizontal sections and to 

 such crypts, which, by their circular outline, may be regarded cut exactly 

 transversely. 



