ERNST G. IIUF 



231 



glands. Tliis area is about one fifteenth of the total cross-sectional area. Not 

 everywhere in a cross section, however, does one find glands. 



If it is assumed that chloride remains extracellular, one can calculate from 

 certain chemical data that the non-chloride space of frog skin is 69.7% (29). 



Fig. 17. Electronmicroscopic view of frog skin. Epidermis and interstitial spaces. Rana 

 temporaria. Arrows pointing to double lines indicating sites of contact between protoplasmic 

 extensions from different epithelial cells (56). (Reproduced from original prints'by courtesy 

 of Prof. Dr. F. S. Sjoestrand, Stockholm.) 



This is about 94% of the total water of skin, a figure which is high as compared 

 to those obtained for other tissues, yet well in line with what has been found for 

 skin in general (42a, 52). Although it is impossible,at this time, to state definitely 

 what the relationship between 'chloride space' and the anatomical 'extracellular 

 space' is, it has been suggested to consider them as identical. On this basis, the 

 conclusion was reached that the cells of the skin, the epithelial cells, that is, con- 

 tain very little or no sodium, whereas they are loaded with potassium. Histo- 



