vii THE STAGES OF LIFE AND DEATH 303 



The kidneys show a form of atrophy throughout the par- 

 enchyma. The colour turns to a reddish brown in most cases, 

 and the surface becomes wrinkled and granular. The atrophy 

 is due to the shrinkage of both the winding and the straight 

 tubules and of the epithelial cells which become shorter with 

 smaller nuclei. The tubules may grow thinner and disappear 

 and their glomeruli be obliterated. 



There has been observed in old people an increase in the size 

 of the supra-renal capsules which become mammillated and 

 convoluted in appearance (Sabrazes and Husnot, 1906). 



The question of the hypertrophy of the prostate gland, which 

 is extremely frequent in old people (occurring, according to 

 Thompson, in 56 per cent of those over 60 years of age), is 

 under discussion, some scientists regarding it as of solely 

 pathological character. 



Symptoms of atrophy are seen also in the gastro-enteric organs ; 

 the mucous membrane becomes thinner, the glands smaller, and 

 the muscular coats thinner. The cells of the various sections 

 contain a light yellowish-brown pigment. 



The thorax of the old differs from that of the young in that 

 it is less mobile and elastic. The lungs of the aged, which were 

 first studied by Magendie, frequently show senile emphysema as 

 well as a certain degree of atrophy. 



The majority of the changes in the peripheral nerves described 

 as characteristic of senility are in all probability connected with 

 morbid conditions, and especially with chronic intoxications. . 



As a rule, the muscular sense and the various forms of 

 cutaneous sensibility appear to be normal, with the exception of 

 the sense of pain, which seems to be somewhat dulled, especially 

 in the upper limbs. The nerves are sometimes painful when 

 compressed, but preserve their normal electric excitability and 

 do not show the reaction of degeneration. 



Numerous changes take place in the organs of sense, more 

 particularly in the eyes and ears. Angelucci considers that the 

 chromatic sense in the old is also liable to change, so that the 

 aged fail to distinguish between white and light yellow, and 

 between blue and green. 



The researches necessary to determine the changes in the 

 senses of touch and smell in old age have not as yet been 

 made. 



The spinal cord of old people shows amyloid bodies to be 

 specially numerous; the changes undergone by the grey matter 

 resemble those in the grey matter of the brain; in the white 

 matter we find atrophy of the medullary sheaths, in consequence 

 of which the whole of the cord shrinks, whilst the outer layer 

 of connective tissue becomes thicker. It is not, however, possible 

 to say for certain whether certain (sensori-motor) systems are 



