ALIMENTATION AND DIGESTION 99 



the other hand, especially meat and fat, the cells (muscle 

 fibers and fat cells) which contain the essential nutrients 

 are held together by connective tissue made up largely of 

 fibers of an albuminoid nature. These fibers are soluble in 

 the juices of the stomach, in which the cellulose which 

 holds together the vegetable foods is insoluble. The full 

 importance of these differences will be evident before we 

 have finished the study of digestion. 



13. The process of alimentation. Before corn, wheat, meat, 

 vegetables, and other food materials can be taken into the 

 body and made to yield up to it the material and power 

 which they contain, they must, in most cases, undergo 

 various preparatory or preliminary processes or treatments 

 which shall make them easier or better to eat or more 

 attractive. The most familiar of these processes is cooking, 

 but it is by no means the only one. In the case of animal 

 food the animal must be captured, if wild, or raised, if 

 domesticated. It must be killed, skinned, dressed, cut up, 

 and the meat in many cases " ripened " by keeping, or 

 " cured " by smoking, salting, drying, or corning. So, also, 

 with plant food, such as cereals, vegetables, fruits, nuts, 

 and the like ; these must first be found, if wild, or grown, 

 if domesticated. They must then be separated from the 

 rest of the plant threshed, if wheat, rye, oats, or barley; 

 husked and shelled, if corn ; dug up or removed from the 

 earth, if vegetables like potatoes, celery, radishes, or lettuce. 

 Fruits and nuts must be separated or picked from vine or 

 tree ; milk must be drawn from animals ; and even salt, water, 

 and condiments like mustard and pepper must be separated 

 from the earth or the sea or from plants. After collection 

 and further preparation by winnowing, grinding, or cleaning, 

 elaborate cooking is applied to many forms of food before it 

 is put upon the table ; and even then, at the last moment 

 before it is eaten, a further separation, as of meat from bone, 

 must be made either by the carver or by the eater himself. 



