LIFE: ITS ORIGIN AND NATURE 25* 
specific purpose. Modern science, however, does 
not believe that these teleological actions in¬ 
volve any theological interpretation. They 
represent, merely, the purposeful manifestations 
of life, which are beneficial to the organism, 
and, if it were not for these, the living body 
would soon die, and the race would become 
extinct. There is some mechanism (or mechan¬ 
isms) within the body, therefore, which regu¬ 
lates its activities, and causes every cell and 
tissue to perform its proper functions. What 
is the nature of this mechanism? 
Briefly, there are two such mechanisms with 
in the body, which control its functions and 
activities. These are (1) the ductless glands, 
and (2) the nervous system. 
(1) Our knowledge concerning the functions 
of the ductless glands is relatively new. Within 
the past few years, it has been ascertained that 
there are, within the body, various ductless 
glands, of which the principal ones are the 
following: (a) The thyroid gland. This gland 
secretes a substance called “thyroxin,” which 
controls, to a large extent, the growth of spe¬ 
cialized organs and tissues—especially those of 
brain and sex. It is also the gland of energy- 
production. (b) The pituitary gland. This is 
divided into two parts, (1) the anterior, and 
(2) the posterior. The anterior portion secretes 
a substance known as “tethalin,” which con¬ 
trols the growth of the skeleton and its sup¬ 
porting tissues. The posterior portion of the 
gland secretes a substance known as “pituitrin,” 
which seems to control the growth and func¬ 
tional activity of the nerve and involuntary 
