508 PROCESSES INFERRED FROM INDIRECT OBSERVATION 



neoplasm (carcinoma) is accelerated by the catalyzer, the growth of 

 young animals prior to sexual maturity is retarded. It might be 

 imagined that this constituted evidence of a fundamental difference 

 between the metabolism of malignant tissue and that of normal tissue. 

 This inference would not be justified, however, because in the first 

 place no other evidence of a fundamental difference between the growth 

 of malignant and of normal tissues has ever been advanced and, in the 

 second place, the accelerative action of these catalyzers upon growth 

 is not by any means confined to the growth of malignant tissues. 

 Thus cholesterol accelerates, as we have seen, the division-rate in 



FIG. 43. Comparison of a normal (left) and a tethelin-fed (right) male white mouse, 

 both one year old and 28 grams in weight. Note the smooth coat and compact form of 

 the tethelin-fed mouse as contrasted with the loose form and rough coat of the normal 

 animal. 



Paramecia. Our clinical experience abundantly confirms the fact that 

 hyperactivity of the pituitary body leads to abnormally rapid develop- 

 ment of bony and Epithelial Tissues and, finally, tethelin markedly 

 accelerates the regeneration of epithelium lost by injury and the regain 

 of weight lost during a period of inanition after the readmission of food. 

 The action of tethelin in hastening the repair of epithelial lesions is so 

 decided that it has been proposed as a means of accelerating the repair 

 of slowly-healing wounds, such as the leg-ulcers which may result from 

 varicose veins. 



We have the apparently opposed facts, therefore, that cholesterol 

 and tethelin definitely accelerate the growth of certain types of tissue, 



