ABSORPTION OF CARBOHYDRATES. 533 



believes that when homogeneous starch solutions are injected intra- 

 venously or subcutaneously, the starch is taken up by the organs, namely 

 the spleen, liver and lungs, and is utilized as the starch can be changed 

 into glycogen. A part of the carbohydrates is destroyed by fermenta- 

 tion in the intestine, with the formation of lactic and acetic acids and 

 other bodies. 



The different varieties of sugars are absorbed with varying degrees 

 of rapidity, but as a general thing absorption occurs very quickly. This 

 absorption takes place more quickly in the upper part of the intestine 

 than in the lower part (ROHMANN, LANNOIS and LUPINE, ROHMANN 

 and NAGANO 1 ). It is generally admitted that the simpler sugars are 

 more quickly absorbed than the disaccharides, while the reports as to 

 the absorption of the disaccharides differ somewhat (HEDON, ALBER- 

 TONI, WAYMOUTH REID, ROHMANN and NAGANO). There seems to be 

 no doubt that lactose is absorbed more slowly than the two other disac- 

 charides. According to the extensive experiments of ROHMANN and 

 NAGANO, saccharose is absorbed more quickly than maltose. NAGANO 2 

 contends that the pentoses are absorbed more slowly than hexoses. 



On the introduction of starch even in very considerable quantities 

 into the intestinal tract no glucose passes into the urine, a condition 

 which probably depends in this case upon the absorption and assimila- 

 tion and the slow saccharification taking place simultaneously. If, 

 on the contrary, large quantities of sugar are introduced at one time, 

 then an elimination of sugar by the urine takes place, and this elimina- 

 tion of sugar is called alimentary glycosuria. In these cases the assimila- 

 tion of the sugar and the absorption do not take place together. 



That quantity of sugar to which we must raise the ingested sub- 

 stance in order to produce an alimentary glycosuria gives, according 

 to HoFMEisTER, 3 the assimilation limit for that same sugar. This limit 

 is different for various kinds of sugar; and it also varies for the same 

 sugar not only in different animals, but also in different members of the 

 same species, as also in the same individual under varying circum- 

 stances. In general it can be said that in regard to the ordinary varie- 

 ties of sugar, such as glucose, fructose, galactose, saccharose, maltose, 

 and lactose, the assimilation limit is highest for glucose and lowest for 

 lactose. It must be admitted that with an overabundant quantity of 

 sugars in the intestinal tract the disaccharides do not have sufficient 

 time for their complete inversion, and this has been directly shown by 



1 Lannois and Lepine, Arch, de physiol. (3), 1; Rohmann, Pfliiger's Arch., 41; see 

 also footnote 3, p. 532. 



2 In regard to the literature on the absorption of sugars, see footnote 3, p. 532. 

 Arch. f. exp. Path. u. Pharm., 25 and 26. 



