"LYMPH. 669 



pulp or oil, which is reddish in the foetus, yellow in childhood, and 

 brown in old age. Under the microscope, the pulp is found to consist 

 of minute oil-like spheroids, of very unequal size, varying from 24ooo tn 

 to g^o^th of an inch in diameter. 1 They continue during life : but with 

 their uses we are unacquainted. By the ancients, they were believed 

 to be the secretory organs of the imaginary atrabilis ; hence their name. 

 Sir Everard Home considers that they act like a filter, " by which any 

 oil left in the arterial branches that are near the kidneys may be sepa- 

 rated and prevented from making its escape by the tubse uriniferse of 

 these glands." Dr. Carpenter 2 thinks the only function that can be 

 assigned them with anything like probability is that of serving as a 

 means of conveying into the veins the blood sent through the renal 

 artery, when, from any cause, the secreting function of the kidneys is 

 partly or wholly checked, and their capillary circulation stagnates in 

 consequence. 



All these bodies are probably concerned in lymphosis ; but at the 

 same time as shown hereafter, they may act under special circum- 

 stances as diverticula to the blood and hence merit the name now 

 generally assigned to them of vascular glands. 



2. LYMPH. 



Lymph may be procured in two ways, either by opening a lymphatic 

 vessel, and collecting the fluid that issues from it, but this is an un- 

 certain method, or by making an animal fast four or five days, and 

 obtaining the fluid from the thoracic duct. This has been considered 

 pure lymph ; but it must be mixed with the product of the digestion of 

 the different secretions from the portion of the digestive tube above the 

 origin of the chyliferous vessels. Chyle itself is nothing more than 

 lymph of the intestines, containing matter absorbed from the digested 

 food ; and in the intervals of digestion lymph alone is found in the chy- 

 liferous vessels. 



The fluid, obtained as above-mentioned, is of a rosy, slightly opa- 

 line tint; a markedly spermatic odour, and saline taste. At times, it 

 is of a decidedly yellowish colour ; at others, of a madder red ; circum- 

 stances which may have given occasion to erroneous inferences from 

 experiments made on the absorption of colouring matters. Its specific 

 gravity has been found, by some, to be 1022-28 : by others, 1-037. Its 

 colour is affirmed to be more rosy in proportion to the length of time 

 the animal has fasted. When examined by the microscope, it exhibits 

 globules or corpuscles like those of the chyle ; and, like the chyle, bears 

 considerable analogy, in its chemical composition, to the blood. Both 

 may, indeed, without impropriety, be regarded as rudirnental blood. 



Bodies similar to these lymph corpuscles are seen mingled with the 

 blood, occupying generally the space between the main current and the 

 parietes of the vessel. Some, however, regard them as blood corpus- 

 cles in process of solution or disintegration ; and M. MandP thinks they 

 do not exist in the fluid during life, but are owing to the coagulation of 



1 Gulliver, in Gerber's General Anatomy, p. 103. 



Principles of Human Physiology, 710, Lond., 1842. 



3 Anatom. Microscop., i. 15. 



