19K).| NATURAL SCIENCES OF PHILADELPHIA. 9 



16 Exfoliation slighl . 



Is Exfoliation slight. 



19.. Exfolial ion slighl . 



30 Exfoliation slight. 



31 Exfolial ion very slighl . 



Mouse 262, 5 to 3-hour Stack. 



Int. — 1 Exfoliation none. 



— 2 Exfoliation slight. 



—3 Exfoliation slight. 



—4 Exfoliation severe. 



—5 '. Exfolial ion moderate. 



—6 Exfoliation mode rate. 



Mouse 250, 5-hour Stage. 



Int . 21 Exfoliation none. 



22 Exfoliation none. 



30 Exfoliation moderate. 



31 Exfoliation moderate. 



32 Exfoliation slight. 



33 Exfoliation moderate. 



Mouse 253, 6-hour Stage. 



Int. 10 Exfoliation slight. 



15 Exfoliation slight. 



16 Exfoliation none. 



19 Exfoliation questionable. 



25 Exfoliation slight. 



27 Exfoliation none. 



28 Exf oliat ion none. 



29 Exfoliation none. 



As already stated, as a result of the method of fixing the mouse 

 intestine, the epithelial row was at times torn loose from the sub- 

 epithelial connective tissue. It thus results that in some cases the 

 material presented a decidedly battered appearance. While, how- 

 ever, the epithelial row itself might thus be torn loose and more or 

 less broken, the individual cells were not thereby injured and their 

 appearance indicated an accurate fixation. 



On the other hand, it was frequently possible to see that the cells 

 at the tips of the villi were abnormal, this abnormality expressing 

 itself in a loss of staining capacity on the part of the cytoplasm and 

 an obvious degeneracy of the nuclei. This degeneracy, at first 

 affecting only the cells at the tips of the villi, passes into a condition 

 in which these cells have disappeared, while those lying along the 

 sides of the villi are affected. This condition, in its turn, passes 

 into one 'in which the villi are represented merely by stumps of 

 connective tissue, the epithelium being present only in the regions 

 between the bases of the villi. Finally a stage is reached in which 

 the intestine is wholly denuded of epithelium. In the lists given 



