192 MODERN SCIENCE READER 



ligible. A few years ago the number of hypothetical enzy- 

 mes in the body was likely to be increased whenever a new 

 research in metabolism appeared, now the drift seems to be 

 in the direction of manufacturing new hormones. This 

 natural inclination to abuse a new and attractive idea will 

 not of course prejudice us against the great importance of 

 the suggestion which we owe to Bayliss and Starling. It 

 is to be hoped only that no one will be tempted to give to 

 these hypothetical hormones distinctive names, except in 

 cases such as the secretin, adrenalin, etc., in which the sub- 

 stances have been isolated in some degree of purity. For 

 once a specific name has become attached to an entirely 

 unknown substance, it acquires henceforth an easy currency 

 in our literature, and soon many of us unconsciously as- 

 sume that the thing so designated constitutes one of the 

 verified facts of our science. By way of example one may 

 cite the thrombokinase which has become such a familiar 

 term in the literature of coagulation and which not infre- 

 quently is employed by writers as though its existence were 

 a settled fact. 



Among his other valuable suggestions regarding the 

 characteristics of the hormones, Starling has called atten- 

 tion to the fact that some of them act by increasing the 

 processes of disassimilation or catabolism, while others ap- 

 parently stimulate the processes of assimilation or growth. 

 In this latter group we may include the hormones of the 

 anterior lobe of the pituitary body, according to the present 

 conception of the functions of that gland, and all of the 

 hormones of the reproductive cells. These latter have in 

 general what has been designated as a dynamogenic action, 

 they cause hypertrophies in various organs or tissues and 

 invoke therefore processes of synthesis rather than those of 

 splitting and oxidation. Hypertrophy as an outcome of 

 increased functional activity is a familiar phenomenon, but 

 as Nussbaum remarks, the hypertrophy induced by testic- 

 ular or ovarian hormones resembles rather the effect of the 

 growth energy exhibited by the developing embryo, in that 



