484 POPULAR SCIENCE MONTHLY 



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sunken; the eyes have fallen far back; the lips are drawn in. All of 

 these changes indicate to us, when we think upon them, the fact that 

 there has been a certain shrinkage and shrivelling of that which is 

 within and beneath the skin. Expressed in technical terms, we should 

 call this an atrophy, and to anatomists the mere sight of the face of a 

 very old person reveals at once this fundamental fact of an atrophy 

 of the parts, an actual loss of some of their bulk, which is one of the 

 most characteristic and fundamental marks of old age. The gait 

 becomes shuffling, the foot is no longer lifted free from the ground, 

 as the old man walks along. He does not rise upon his toes, but the 

 sole of the foot is kept nearly flat and as he drags it cumbrously for- 

 ward it is apt to strike upon the sidewalk. This indicates to the 

 physiologist a lessened power in the muscles, a lessened control over the 

 action of these muscles, an inferior coordination of the movements, so 

 that there has been in the old man, judged by his gait alone, a physio- 

 logical deterioration as well as an anatomical atrophy. You notice 

 too his slow speech, often difficult hearing, and imperfect sight. All 

 of these qualities show a loss, and we commonly think of the old as 

 those who have lost most, who have passed beyond the maximum of 

 development and are now upon the path of decline, going down ever 

 more rapidly. One of the chief objects at which I shall aim in this 

 course of lectures will be to explain to you that that notion is erroneous, 

 and that the period of old age, so far from being the period of true 

 decline, is in reality essentially the period in which the actual decline 

 going on in each of us will be least. Old age is the period of slowest 

 decline — a strange, paradoxical statement, but one which I hope to 

 justify fully by the facts I shall present to you in this course. In 

 the old person you note that there is in the mind some failure and 

 also loss of memory — less mental activity, greater difficulty in grasp- 

 ing new thoughts, assimilating new ideas, and in adapting himself to 

 unaccustomed situations. All this betokens again the characteristic 

 loss of the old. And as we turn now from these outward investiga- 

 tions to those which the anatomist opens up to us, we learn that in 

 the interior of the body, and in every organ thereof, the species of 

 change which I have referred to as characteristic of the very old, is 

 going on and has become in each part well marked. Let us first 

 examine the skeleton. In youth many parts of the skeleton are soft 

 and flexible, like the gristles and cartilages, which join the ribs to 

 the breastbone, but in the old man they are replaced by bone. 

 Bone represents an advance in organization, in structure, as we say, 

 over the cartilage. The old man has in that respect progressed be- 

 yond the } r outhful stage; but that progress represents not a favorable 

 change; the alteration in structure from elastic cartilage to rigid 

 bone is physiologically disadvantageous, so that though the man has 

 progressed in the organization or anatomy of his body, he has really 



