CARBOHYDRATES AND INORGANIC CONSTITUENTS 415 



who found glycogen microscopically in 447 (or 29 per cent.) of 

 1544 tumors examined. It was present in but 3 out of 184 

 fibromas, osteomas, gliomas, hemangiomas, lipomas, and lymph- 

 angiomas, and in but 2 out of 260 adenomas from various 

 parts of the body. It occurred in all teratomas, rhabdomy- 

 omas, hypernephromas, and syncytiomas. In 138 sarcomas 

 glycogen was present in 70 (50.7 per cent.); of 415 carcino- 

 mas it was found in 181 (43.6 per cent.). In the squamous 

 epithelial cancers 70 per cent, contained glycogen, while the 

 mucoid or colloid cancers were always free from glycogen. 

 The glycogen undoubtedly enters the cells from without, prob- 

 ably entering as sugar, and being converted into glycogen by 

 intracellular enzymes. We have no reliable studies of the actual 

 quantity of glycogen in various tumors, although Meillere 1 

 states that the microscopic and chemical examination of tumors 

 give corresponding comparative results, which Gierke states is 

 generally true with glycogen estimations. 



Pentoses. Neuberg 2 reports finding, as a product of autol- 

 ysis of a carcinoma of the liver, a pentose which was not pro- 

 duced by autolysis of either normal liver tissue or the primary 

 growth in the stomach. Beebe 3 found that in carcinoma of 

 the mammary gland the percentage of pentose (xylose) is some- 

 what higher than the amount in normal mammary glands 

 (about 0.23 per cent.). Carcinoma in the liver did not show 

 any constant excess of pentose above that of normal liver tissue 

 (about 0.38 per cent.). A primary carcinoma of the liver 

 showed quite the same pentose and phosphorus content as nor- 

 mal liver tissue. In general, no constant relation of pentose 

 to origin, malignancy, or degeneration of tumors was observed. 

 The most significant suggestion of this and other work by the 

 same author is that the composition of a metastatic growth 

 may be modified by its environment, so that it may differ from 

 the primary growth more than from the normal tissue in which 

 it has taken root. 



(3) Inorganic Constituents. These have been studied 

 under exceptionally favorable conditions, in that the age of the 

 tumor could be accurately estimated, in the inoculable carcin- 

 oma of mice (Jensen), by Clowes and Frisbie. 4 They found 

 that rapidly growing tumors contain a high percentage of potas- 

 sium and little or no calcium, whereas in old, slowly growing, 



Rend. Soc. Biol., 1900 (52), 324. 

 2 Berl. Win. Woch., 1904 (41), 1081 ; 1905 (42), 118. 

 3 Amer. Jour. Physiol., 1905 (14), 231. 

 *Amer. Jour. Physiol., 1905 (14), 173. 



