186 LECTURE IV. 



still further changes ; and this tube is also 

 subdivided into two parts, and different 

 functions are allotted to each. Glandular 

 structures are also added, which prepare 

 fluids subservient to the functions of the 

 intestinal canal." 



In the small intestines, the food is con- 

 verted, in the higher order of animalsj 

 into chyle, which is a fluid very much 

 resembling blood, and chiefly differing 

 from it in its colom- ; so speedily and so 

 •nearly is the ultimate object of sanguifi- 

 cation accomplished. The effect produced 

 on the food in the intestines will be in 

 proportion to the secreting surface of the 

 canal, which pours on it peculiar liquors, 

 •and to the duration of its stay in the bow- 

 els. These objects are accomplished by 

 the length and convoluted form of the canal; 

 by its lining projecting and being formed 

 into plaits, either transverse, longitudinal, 

 spiral, or reticulated ; by the formation of 

 smaller fossae or larger sacculi. Every 

 variety in the animals hereafter mention- 

 "ed is displayed, and so beautifully are the 



