500 The University Science Bulletin. 



A rapid utilization of these substances must lead to a rapid atrophy 

 and death, according, also, to the formulation given above. 



Such a reorganization, it is evident, cannot take place in early life 

 except under the influence of most powerful external stimuli or de- 

 velopmental defects. It becomes, however, more possible in later 

 life when the normal forces which maintain the normal heterogenic- 

 ity are waning. Cancer represents such a form of active growth. 

 It is a disease peculiar to later life. It occurs earlier in connective- 

 tissue areas than in epithelial tissue. The connective-tissue cells, 

 according to the above observations, lose their property for inde- 

 pendent growth earlier than the epithelial tissue. 



In previous publications ^ I have noted that cancerous tissue 

 grows like that of younger embryos and liberates the same or a 

 similar growth stimulus.^^ In the body cancer may result from 

 congenital abnormalities, such as pigmented moles. It occurs more 

 frequently in certain families of mice (Maude Slye). It follows the 

 continuous application of many growth stimuli or substances capa- 

 ble of effecting such a reorganization. In man, as pathologists agree, 

 it follows most frequently upon long-standing chronic inflamma- 

 tion (Billroth).=^« 



As has long been fully appreciated, the impediment which has 

 stood in the way of advance in cancer has been the inadequacy of 

 our knowledge of the cell and its relation to the whole. It has been 

 the endeavor of the cancer laboratory in St. Louis to attack the 

 problem from this routg. Cancer is not a parasitic disease. It is a 

 disease which follows after long, continuous stimulation. Before 

 cancer can be understood it is necessary that irritability and stimu- 

 lation be reduced to simple terms. The essential conditions for 

 mechanical dedifferentiation, or loss of function, and the production 

 of an active growth of cells like that of cancer is the presence of 

 substance capable of removing the "L." This "L" has many of the 

 properties of the phospholipins isolated by Mills. These phospholi- 

 pins are soluble in many lipoid solvents, and especially products of 

 coal tar. We have studied the action of coal tar, and find that it be- 

 haves in the tissue like the substance liberated by the cancerous 

 tissue and the tissue of young embryo which is able to combine with 

 or otherwise remove the "L" from the cells. Coal tar thus attracts 

 the cells to it and effects their dedifferentiation. At first it occasions 

 their disintegration. Later it becomes a less active solvent and 

 occasions an active proliferation of these cells. It is capable not 

 only of producing many of the symptoms of cancer by itself, but of 



