428 THE GLANDULAR ORGANS. 



sides have been encountered. Gulewitsch further demonstrated that 

 arginin is a normal constituent of the spleen. 



Of ferments a proteolytic ferment has been discovered in the 

 spleen and in the thymus gland by Kutscher, Conradi and Row- 

 land. 



THE KIDNEYS. 



In addition to the common albuminoids which enter into the com- 

 position of the supporting tissue of the kidneys, we find the common 

 extractives, viz., nucleinic bases, uric acid, urea, leucin, inosit, gly- 

 cogen, fats, and at times taurin. All these substances, however, are 

 present in only small amounts. On one occasion, in the ox, cystin 

 has also been encountered, but it is questionable whether this is a 

 constant constituent of the organs. Of albumins, Halliburton has 

 isolated a globulin and a nucleoproteid, with coagulation-points of 

 52 C. and 63 C., respectively. In addition, a mucin-Jike body 

 has been found, which does not yield a reducing substance, however, 

 on boiling with mineral acids, and which is probably a nucleopro- 

 teid. It is notably found in the papillary portion of the kidneys, 

 while the other nucleoproteid is principally met with in the cortical 

 portion. Serum-albumin is said to be absent. 



THE MAMMARY GLANDS. 



The chemical composition of the mammary glands has not been 

 studied in detail. We know, however, that the protoplasm of 

 the functionally active glands is rich in albumins, and it appears 

 that, as in the case of the pancreas, a very complex nucleo-gluco- 

 proteid is here also present, and is probably intimately concerned in 

 the formation of two of the most important constituents of the milk, 

 viz., the casein and lactose. It may be obtained in solution by first 

 washing the gland thoroughly in water, so as to free it from milk ; 

 it is then extracted with a 0.5 pro mille solution of sodium hydrate 

 at ordinary temperatures. Such solutions also contain the common 

 albumins, and represent an exceedingly viscid, stringy fluid, from 

 which the proteid in question can be precipitated by acidifying care- 

 fully with dilute acetic acid. On boiling with dilute acids the sub- 

 stance is decomposed into albumin, phosphoric acid, and a reducing 

 substance of unknown composition. On digestion with gastric juice 

 it yields a paranuclein. 



As in the case of the pancreas, the substance is decomposed by 

 boiling the gland with water. A coagulable albumin and a nucleo- 

 glucoproteid, which is somewhat less complex than the original sub- 

 stance, thus result. From this solution the proteid can be precipi- 

 tated by the addition of a dilute acid. Like its mother-substance, 

 it also yields a reducing substance on hydrolytic decomposition. 

 Of the relation of the latter to lactose nothing is known, but it is 

 noteworthy that this is formed on standing if a functionally active 



