CHAPTER XVI 



THE INDIVIDUAL AS AN ADAPTIVE MECHANISM 



HAVING now presented some evidence which sug- 

 gests the mechanistic character of certain organic proc- 

 esses in man, let us roughly sketch his career as an 

 individual, upon the assumption that he is an adap- 

 tive mechanism, dependent for life, as for death, upon 

 the physical conditions of his internal and external 

 environment. 



The life of the individual begins with the union of 

 the spermatozoon and ovum. As far as the initiation 

 of development is concerned, this, as Loeb has shown, 

 is essentially a physico-chemical phenomenon. The 

 fertilized ovum may be ejected from the end of the 

 fallopian tube ; or, after reaching the uterus, it may 

 be cast off in a hemorrhage caused by a submucous 

 fibroid ; in either case, it is a mechanistic end. The 

 fetus may fail to thrive or develop in the uterus of a 

 syphilitic mother the chemical change in whose tissues 

 is produced by a parasite a spirochete, the activity 

 of which may be checked by a chemical agent mer- 

 cury. Again, the life of a fetus in a normal uterus may 

 be terminated if the mother be physically injured or be 

 the subject of strong emotion. In either case, the end 

 is mechanistic. 



The life of the individual may be terminated at birth 



366 



