36 Trans. Acad. Sci. of St. Louis 
tion of stomach, intestines and many other things vary 
greatly, in general corresponding to the type of indi- 
vidual. The stomachs of slender persons are nearly 
twice as slow in evacuating food as are the stomachs 
of heavy people, probably as an adaptation of nature— 
the heavy person needs more food consequently his stom- 
ach operates more rapidly. It has been found that 
defecation is normally much more frequent in heavy peo- 
ple; as a rule, perhaps two or three times a day. In 
certain slender types there is a question as to whether 
or not a daily action is necessary—though this with cau- 
tion. In similar fashion blood pressure is lower in slen- 
der people and higher in those of heavier type. Certain 
digestive juices are weaker in certain slender types and 
stronger in others, and so on through the whole list of 
bodily functions. To complicate the situation there is 
also a relationship of visceral, physical and physiological 
peculiarities to age. We look at persons and guess their 
age with fair accuracy—at least to ourselves—but what 
makes one person look old and another middle-aged? We 
see only the surface of the body. These surface pe- 
culiarities are but reflections of deep interior changes. 
The shape of the viscera, heart, stomach, intestines, all 
may indicate the age to a practiced observer as readily 
as does the face or figure. Who then is normal? Is 
grey hair abnormal? Not in some. No one has ever 
successfully defined normal though anyone may ask what 
is normal—for instance what is normal blood pressure? 
We must judge each person individually, anatomically 
and physiologically, just as we judge them in every day 
life individually, and as we unconsciously do, as in- 
fluenced by age, bodily type, and the like. 
May I suggest another difficult subject. We never 
did understand, we only thought we understood, some- 
