132 LYMPHATIC SYSTEM. 



up to the loins at h, and goes under the aorta in different 

 branches, getting from the left side to the right, and joining 

 the thoracic duct. Another part passes under the iliac arteries 

 and appears upon the os sacrum at /, making a beautiful 

 network, joining the lymphatics of the right side, and passing 

 under the right iliac artery, to form the network g upon the 

 upper part of the right psoas muscle. In different parts of 

 this course from Poupart's ligament to the loins, and also in 

 the loins themselves, there are, in most subjects, many lymphatic 

 glands ; none of which were filled in the subject from which 

 this plate was made. 



The lymphatic vessels of the right side, joined by some from 

 the left, having now reached the right lumbar region, appear 

 there in the form of a plexus of large vessels, and pass through 

 several glands, which in this subject occupied the spaces (i, i, i} } 

 but not being injected with mercury are not represented ; at 

 this part likewise they receive large branches, under the aorta, 

 from the plexus on the left side of the loins, as is mentioned 

 before, and having at last got up as high as the second lumbar 

 vertebra, they all join, and form a single trunk called the tho- 

 racic duct, which is seen at m Plate II. At this part they are 

 likewise joined by the lacteals, which I shall next describe. 



The lacteal vessels, so called from their commonly conveying 

 a fluid that is of the colour of milk, begin from the inner sur- 

 face of the intestines, where they have patulous orifices (see 

 Note LXXXIII) destined to imbibe the nutritious fluid or chyle ; 

 from the cavity of the intestines these vessels pass obliquely 

 through their coats, uniting as they go so as to form larger 

 branches. These branches run on the outside of the gut to 

 get to that part which is next the mesentery ; and, whilst they 

 are yet upon the gut, they are sometimes of a size sufficient to 

 admit a small pipe, so that I have injected them with mercury 

 even in the human subject. 



From the intestines they run along the mesentery and meso- 

 colon, towards the spine, and in their way they pass through 

 the conglobate or mesenteric glands, which in the human sub- 

 ject are very numerous. These glands divide the lacteals into 

 two regions; for from the intestines to the glands these vessels 

 are called lactea primi generis, and from the glands to the 

 thoracic duct, lactea secundi generis. 



