1030 CHARACTERISTICS OF DIFFERENT AGES. 



more rapid than their renovation, a progressive loss of substance must take 

 place. The forms of Degeneration most commonly met with in advanced 

 age, are the fatty and the calcareous. The former ( 351) is extremely prone 

 to show itself in those organs whose integrity of structure is peculiarly im- 

 portant to health, and whose deterioration interferes directly with the vital 

 properties of their component tissues. Thus we observe it in the Muscular 

 apparatus generally, but pre-eminently in the walls of the Heart ; and in 

 proportion as its contractile fibre has been replaced by particles of fat, must 

 the vital energy of any muscle be lowered. So, again, we find the same 

 degeneration in the Liver, Kidney, and other parts of the Glandular appa- 

 ratus ; the proper secreting action of which is impaired in the ratio of the 

 substitution of fat for the proper Glandular elements. But it may also lead 

 to most serious derangements of the vital functions, by its interference with 

 the purely mechanical actions of certain parts of the organism ; thus, fatty 

 degeneration of the walls of the Bloodvessels is one of the most frequent 

 causes of those extravasations of blood in the nervous centres, which give 

 rise to the apoplexy and to the various forms of paralysis so common among 

 the aged ; and the same change occurring in the Bones, gives them that 

 peculiar brittleness which they frequently exhibit in advanced periods of 

 life. That general decline of the vital powers, which has received the name 

 of " climacteric disease," appears traceable to the same source. 1 The ten- 

 dency of the calcareous degeneration (which especially affects the Cartilag- 

 inous and Fibrous tissues) is almost exclusively to interfere with the mechnn- 

 ical adaptations of the organism ; producing an injurious rigidity in various 

 structures which require a greater or less amount of flexibility for the normal 

 performance of their functions. Thus it is very common for the cartilages 

 of the ribs to become ossified in advanced life, so as to interfere with the free 

 movement of the walls of the thorax ; and the thyroid cartilages of old 

 people are frequently converted into bone, producing a roughness of the 

 voice, and deficiency of the power of modulating it. The intervertebral 

 substance (which is partly cartilaginous and partly fibrous) not unfrequently 

 becomes solidified in the lumbar region, as do also the spinal ligaments, so 

 that several of the lower vertebrae are firmly auchylosed to each other and 

 to the sacrum ; and a like change often takes place in the pelvic articula- 

 tions, so that the pelvis and the lower part of the spine become one contin- 

 uous mass of bone, destitute of flexibility or yieldingness in any part. In 

 like manner the cranial sutures often become obliterated, and calcareous 

 deposits occur in the duplicatures of the dura matter forming the falx and 

 tentorium. A large amount of this kind of change may take place without 

 any serious interference with the organic functions, although it tends to cur- 

 tail the Animal powers. When the calcareous degeneration, however, extends 

 itself to the vital organs, the interruption which it occasions in their actions 

 may be fatal ; thus, next to fatty degeneration, there is probably no more 

 frequent cause of failure of the heart's action, or of extravasation from the 

 bloodvessels, in old persons, than ossification of the valvular apparatus of 

 the former, depriving it of the flexibility which is essential to its proper 

 action, or the fibrous Avails of the latter, imparting to them a brittleuess 

 which predisposes to rupture. 2 



878. Thus, then, with the advance of Old Age, the organism becomes 

 progressively m0 re and more unfit for the active performance of its vital 



1 See Gulliver in the Transact, of Roy. Med.-Chir. Soc., 1843; and in Edin. Mod. 

 and Suric. J<>urn., 1843; Mr. Barlow's General Observations on Fatty Degeneration, 

 in the Medical Times and Gazette, May 15th, 18.V2. 



2 A ,,'()< xl account of these changes will be found in the Practical Treatise on the 

 Diseases and Infirmities of Advanced Life, by Daniel Maclachan, M.D., 1863. 



