178 JouENAL OF THE MiTCHELL SociETY [February 



rounding tissue of indigestible cellulose, will escape conversion 

 into soluble food products. Therefore, if the starch be fed 

 wholly uncooked it must be allowed more freely in the diet 

 because a greater part will never become available as food ma- 

 terial. This is strikingly shown in a vegetarian or fruitarian 

 diet where the uncooked carbo-hydrate proportion is allowed in 

 such quantities. To offset this condition we must bear in mind 

 that this kind of starch or carbo-hydrate food will assist in fill- 

 ing the intestine with an indigestible mass of fibre which 

 plays an important function in stimulating peristaltic action 

 and giving character to the feces. If the carbo-hydrate be fed 

 in the form of cooked starch, the hard granules have been rup- 

 tured and the first stage of starch digestion has begun. The 

 swelling and hydration has taken place and a certain amount 

 of soluble starch and dextrin have already been formed. 



Such a carbo-hydrate mass is capable of very rapid conversion 

 into soluble sugars under the influence of deliberate mastication 

 in the presence of an active saliva. Those of us who have many 

 times witnessed the action of such diastatic enzymes as ptyalin, 

 pancreatic, lipase, or maltase upon a well cooked and partly 

 dextrinized starch at body temperature have been impressed 

 with the rapidity of this enzyme action in comparison Avith 

 the slower action of pepsin and trypsin upon the proteins. It 

 has been shown that the three pancreatic enzymes capable of 

 digesting proteins, carbo-hydrates and fats are found in the 

 intestine of the new-born infant from the very first. There- 

 fore, we may expect a co-operation between the saliva and the 

 pancreatic juice in the breaking up of starches, even in early 

 life. Where it is of interest to spare the diastatic digestion any 

 extra work, or where the individual does not ''handle" his 

 carbo-hydrate well, we naturally turn to the soluble sugars and 

 it matters not greatly which one we may select. In some recent 

 experimental work in animal feeding, lactose has indicated 

 some superiority to the other sugars of the diet, but at present 

 that information is incomplete and is not available. 



Just what the amount of this carbo-hydrate portion should be, 

 depends u]3on the proportion of protein and fats. You will recall 



