viii:mistIx'Y of tumohs j\ aESEitAi, 497 



squamous epitlieliuni, whiuli tissues iioniuilly cuntaiu inucli g-lyeogen, 

 are likewise provided with an abundance of this material. Second, 

 the occurrence of areas of impaired cell-iuitrition favors the accumu- 

 lation of lilycogen in the degenerating tumor-cells, just as it leads to 

 a similar accumulation in all other tissues (Gierke).-^ The most ex- 

 tensive consideration of this topic is reported by Lubarsch,-" who 

 found glycogen microscopically in 447 (or 29 per cent.) of 1544 tumors 

 examined. Jt was i)resent in but 3 out of 184 fibromas, osteomas, 

 glionuis, hemangiomas, lipomas, and lymphangiomas, and in but 2 out 

 of 260 adenomas from various parts of the body. It occurred in all 

 teratomas, rhabdomyomas, hypernephromas, and syncytiomas. In 138 

 sarcouuis 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, probably entering as sugar, and being 

 converted into glj'cogen by intracellular enzymes. "We have no re- 

 liable studies of the actual quantity of glj'cogen in various tumors, al- 

 though Meillere ^° states that the microscopic and chemical examina- 

 tion of tumors give corresponding comparative results, which Gierke 

 states is generally true with glycogen estimations. 



Pentoses. — Neuberg ^^ reports finding, as a product of autolysis of a 

 carcinoma of the liver, a pentose which was not produced by autolysis 

 of either normal liver tissue or the primary growth in the stomach. 

 Beebe ^- found that in carcinoma of the mammary gland the per- 

 centage of pentose {xylose) is somewhat 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 normal 

 liver tissue. In general, no constant relation of pentose to origin, 

 malignancy, or degeneration of tumors was observed. 



Purines and Purine Enzymes. — The purines of both benign and 

 malignant tumors have been studied by Wells and Long,^" who found 

 them the same as those in nonnal tissues, and in much the same rela- 

 tive proportions. The proportion of the total nitrogen of tumors which 

 is constituted by the purine nitrogen is less than would be expected 

 from the histological evidence of the amount of nuclear material con- 

 tained in the tumors. Tumors also seem to contain much the same 

 purine enzymes as the normal tissues. Thus, guanase seems uni- 

 versally present in tumors derived from human tissues, and adenase 



28 Ziegler's Beitr., 1005 (37), 502. 

 29Virchow's Arch., 1006 (183), 18S. 

 3oCompt. Pvend. Soc. Biol., 1000 (52), 324. 

 31 Berl. klin. Woch.. 1004 (41). lOSl ; 1005 (42), 118. 

 32Amer. Jour. Physiol., 1005 (14), 231. 

 33 Zeit. f. Krebsforsch., 1013 (12), 508. 

 32 



