134 



DIGESTION 



E 



- A 



means of their blood-vessels, absorb its fluid contents, just as 

 the spongioles which terminate the rootlets of plants imbibe 



moisture from the sur- 

 rounding soil. 



38. Secondly, absorption 

 is also effected by the lac- 

 teals, a set of vessels pecul- 

 iar to the small intestines. 

 These have their begin- 

 nings in the little villi just 

 mentioned, side by side 

 with the blood-vessels. 

 These two sets of absorb- 

 ents run in different 

 courses, but their destina- 

 tion is the same, which is 

 the right side of the heart. 

 The lacteals receive their 

 name from their milky- 

 white appearance. After a 

 meal containing a portion 

 of fat, they are distended 

 with chyle, which they are 



specially adapted to receive; at other times they are hardly 

 discernible. The lacteals all unite to form one tube, the 

 thoracic duct, which passes upward through the thorax, or 

 chest, and empties into a large vein, situated just beneath the 

 left collar-bone. 



39. The Absorbents. The4acteals belong to a. class of ves- 

 sels known as absorbents, or IjTapliatic^ which exist in nearly 

 all parts of the body, except the brain and spinal cord. The 

 fluid which circulates through the lymphatics of the limbs, and 

 all the organs not concerned in digestion, is called lymph- 

 This fluid is clear and colorless, like water, and thus differs 



B 



FIG. 30. THE LACTEALS 

 A, Small Intestine B, Lacteals 

 C, Thoracic Duct D, Absorbents 



E, Blood-vessel 



38. How is absorption effected in another way ? Describe it. Name of the lacteals ? 

 Thoracic duct ? 



39. The absorbents ? Lymph ? What further of the lymph ? 



