MA]\r 215 



meets us. Is man's life at present as long as it 

 should or can be ? The question is exceedingly dif- 

 ficult, but a negative answer seems more probable. 

 "We cannot but hope that, with a better knowledge of 

 our physical structure, a clearer vision of the dangers 

 to which we are exposed, more study of the laws of 

 physiology, heredity, and of our environment, and above 

 all, less reckless disregard of these in a mad pursuit of 

 pleasure, wealth, and position, man's period of mature, 

 healthy, and best activity may be lengthened, perhaps, 

 even a score of years. The mitigation of hurry and 

 worry alone, the two great curses of our American civ- 

 ilization, might postpone the collapse of our nervous 

 systems longer than we even dream. And if we could 

 add even five years to the working life of our states- 

 men, scholars, and discoverers, the work of these last 

 five years, with the advantage of all previously ac- 

 quired knowledge and experience, might be of more 

 value than that of their whole previous life. Human 

 advance could not but be greatly, or even vastly, accel- 

 erated. 



Moreover, we have seen that the history of verte- 

 brates is really the history of the development of the 

 cerebrum, forebrain or large brain, as we call it in 

 man. This is the seat in man of consciousness, thought, 

 and will. This portion as a distinct and new lobe first 

 appears in lowest vertebrates, increases steadily in size 

 from class to class, reaches its most rapid development 

 by mammals, and its culmination in man. During the 

 tertiary period — the last of the great geological pe- 

 riods — ihe brain in many groups of mammals increased 

 in size, both absolutely and relatively, eight to ten- 

 fold. Dr. Holmes says, that the education of a child 



