236 THE LYMPH 



inference it may therefore be concluded that the fat content of the 

 lymph varies directly with the intensity of the absorption of this food- 

 stuff. Thus, it is not uncommon to obtain as low a value as 0.06 per 

 cent, during fasting, and values as high as 15 per cent, during periods 

 of very active fat absorption. In this connection, attention should be 

 called to the fact that the lymph does not aid in the absorption of the 

 proteins, but plays a part, although rather insignificant, in the absorp- 

 tion of sugar. As will be shown later, these substances do not enter 

 the lymph but are transferred in largest part into the blood-capillaries 

 of the intestine. 



The microscopic examination of clear lymph reveals numerous 

 colorless corpuscles belonging to the group of the Ijrmphocytes. 

 Rather poor in cytoplasm these cells display a prominent nucleus. 

 They arise in the Ijnnphatic glands and nodes with which the lymph 

 channels are beset and hence are always present in greater numbers in 

 the lymph leaving these structures than in that entering them. A 

 similar difference in the formed constituents of the lymph is noticeable 

 in lymphoid tissues, such as the tonsils, thymus, spleen, and the differ- 

 ent patches and glandular follicles of the intestine. This fact clearly 

 shows that the organs just enumerated serve as places of origin for 

 these cells, whence they are eventually flushed into the blood-stream 

 to become one of the varieties of circulating white corpuscles. 



The appearance of the different lymph-Uke fluids mentioned prev- 

 iously is very similar to that of the intravascular lymph. Normal 

 cerebrospinal fluid is perfectly clear, colorless, slightly salty, and free 

 from formed elements.-^ Its specific gravity varies between 1.002 and 

 1.008; its reaction is slightly alkaline. Its content in glucose (0.05 to 

 0.1 per cent.) corresponds to the amounts of sugar present in other 

 serous fiuids. Brief reference should also be made at this time to the 

 fact that intracellular glycogen has been found to exist in the cells 

 of the choroid plexus ;2 in fact, it appears that the cerebrospinal fluid 

 is [a true secretory product of this organ. ^ This contention is based 

 upon the observation that the formation of this fluid may be acceler- 

 ated by extract of brain or retarded by extract of thyroid. The 

 cerebrospinal liquor does not coagulate spontaneously, because it does 

 not contain fibrinogen, but may be made to clot by the addition of 

 small quantities of blood or lymph. This fact accounts for the peculiar 

 phenomenon that this fluid frequently clots in the course of inflamma- 

 tory conditions or after injuries to the nervous tissue. Obviously, 

 lesions of this kind enable the elements of the blood to enter this fluid. 

 The total quantity of cerebrospinal fluid is estimated at 60 to 150 c.c. 

 of which 20 to 30 c.c. are contained in the ventricles. 



1 Anglada, Le liquide c^phalo-rachidien, Paris, 1910 (Literature) ; also see : Plaut, 

 Rehm and Schottmiiller, Leitf. zur Untersuchung der Zerebrosp. Fltissigkeit., Jena, 

 1913. 



* Goldman, Archiv fiir klin. Chir., ci, 1913. 



' Dixon and Halliburton, Jour, of Physiol., xlvii, 1913, 215. 



I 



