334 



DIVERSIONS OF A NATURALIST 



anatomists to trace the fine branches of the lacteals 

 uniting branch to branch, and at last forming a large 

 trunk — called the thoracic duct — about 

 a quarter of an inch thick, which runs 

 up the inner face of the backbone to the 

 neck, where it joins the great left sub- 

 clavian vein, and pours its contents into 

 the blood-stream which is there nearing 

 the heart. A small trunk formed by 

 the union of lymphatic vessels from the 

 right side of the head and neck and 

 the right upper limb 

 Fig. 43. — The opens into the right sub- 

 clavian vein. It took 

 some time to discover 

 this smaller trunk, since 

 it is not brought to 

 view by milky contents: 

 Gradually it was made 

 out that there are in- 

 numerable transparent 

 branches opening into the 

 thoracic duct from the 

 whole of the body, be- 

 sides the milky-looking 

 lacteals: branches which 

 bring " limpid" clear fluid, 

 or " lymph," from all the 

 viscera, from the muscles, 

 and from the deeper 

 layers of the skin in every 

 region of the body, even 

 from the toes, fingers, and 

 tongue tip. In fact, wherever the blood-vessels take 

 blood there are also vessels of the lymphatic system 



fore - arm of 

 man, with the 

 skin removed 

 so as to show 

 the large sup- 

 erficial lym- 

 phatic vessels 

 resting on the 

 muscles. They 

 are represent- 

 ed as white 

 knotted cords. 

 On the palm 

 of the hand 

 (8, 8) and on 

 the fingers a 

 closer network 

 of these ves- 

 sels is repre- 

 sented, but 

 the smaller 

 lymphatic cap- 

 illaries and 

 spaces are not 

 shown. 



