350 Vitamines and Deficiency Diseases [June-September 



I have shown (157) that mouse tumor can be successfully implanted 

 in rats, for three generations, if the rats are fed on mouse-tumor 

 tissue, The latter result demonstrates the necessity of a specific 

 food supply for tumor growth. The fact is demonstrated, also, by 

 the inhibition of tumor-growth in pregnant animals, as has lately 

 been shown by v. Graff (158). 



That there are substances which stimulate growth we know 

 from the activity of glands of internal secretion, especially of the 

 anterior lobe of the pituitary. Robertson and Burnett (159) have 

 found that emulsions of anterior lobe of this gland stimulate very 

 markedly the growth of primary Carcinoma in rats, whereas liver 

 emulsion had not the slightest effect. I should like to point out, here, 

 the necessity of further research regarding the activity of pituitary 

 gland (anterior lobe) on Cancer. We know that this gland is im- 

 portant in regulating the growth of the organism. When the an- 

 terior portion of the gland is extirpated from animals, they remain 

 stunted. This is also true, of course, of other glands of internal 

 secretion but it is not so marked as in the case of the pituitary. On 

 the other band, the occurrence of adenomas of the anterior lobe is 

 not infrequent. As a consequence of this abnormality, there is in- 

 creased activity of the anterior portion of the pituitary. In children 

 such abnormality produces Symmetrie exaggerated growth of the 

 individual (gigantism). Between the age of 20-30 such general 

 growth is no longer possible and the adenoma produces exaggerated 

 growth of the bones of the extremities and the skull (acromegaly). 

 It is conceivable that, in later life, when gigantism and acromegaly 

 are no longer possible, increased activity of the pituitary gland may 

 be responsible for the production of tumors. 



When one considers that the symmetrical orientation of organs 

 in a growing embryo must be accomplished by chemical substances 

 and that growth in a seed is brought about by a renewal of enzymic 

 activity, which transforms inactive substances (possibly vitamines) 

 into new substances which stimulate cell division, one is not far 

 from a chemical conception of Cancer etiology. 



The idea that the etiology of tumors can possibly be explained 

 by the existence of specific growth-promoting substance received a 

 new impetus from Rous's discovery of tumors, in fowls, that could 



