ATROPHY. 559 



removed after a short time by the enlargement of the collateral vessels. Yet 

 there are peculiar circumstances under which this does not take place ; thus 

 Mr. Curling has shown that atrophy may occur in fractured bones, in that 

 portion which is cut off from the direct supply of blood through the great medul- 

 lary artery ; the circulation being restored by anastomosis to such an extent as 

 to prevent the death of the bone, but not so completely as to support vigorous 

 nutrition. 1 The most frequent cause of Atrophy lies, however, in the deficiency 

 of formative power in the tissues themselves, arising from the decline of that 

 capacity which they inherit from the germ. This decline, as already shown, 

 takes place in the body at large, as a part of the regular order of things, with 

 the advance of years, and also normally occurs in particular organs at earlier 

 periods of life ; but it sometimes takes place prematurely, either in the body at 

 large, or in particular organs, so that they undergo a wasting or degeneration 

 without any ostensible cause. A remarkable example of this has been already 

 referred to, in the account of Cartilage ( 253) ; and many similar cases might 

 be cited. There is reason to believe that " fatty degeneration/' the form under 

 which degeneration most commonly presents itself ( 593), is in reality far more 

 frequent than simple wasting of the tissues ; but it attracts less notice, because 

 their bulk is little or not at all diminished ; and it is only when their function 

 becomes impaired, that attention is seriously drawn to the change. This form of 

 Atrophy can seldom be attributed to antecedent diminution in functional activity; 

 for it is most common in organs upon which there is the most constant demand for 

 the energetic performance of their respective duties, as, for instance, in the heart, 

 the kidneys, and the liver. But the formative activity of Muscles and Nerves is so 

 closely dependent, as already several times pointed out, upon the active exercise 

 of their functional powers, that atrophy is certain to supervene if this be inter- 

 rupted ; and this atrophy may or may not present itself under the form of fatty de- 

 generation ; a shrinkage of the parts, concurrently with the production of an in- 

 creased amount of fat in them, being perhaps the mode in which it most frequently 

 takes place. Atrophy of one part, moreover, may be dependent upon atrophy 

 or imperfect functional activity of another, if the two be so related in their 

 normal functions that a decline of one involves a corresponding decline in the 

 other. Thus if a motor nerve be paralyzed, the muscles which it habitually 

 calls into action will be atrophied ; and this will equally happen, whether the 

 want of motor power depend upon a deficient production of it in the nervous 

 centres, or upon an interruption to its conduction through the trunks. 3 On the 

 other hand, if the muscles of a part undergo degeneration from want of use (as 

 in disease of the hip-joint), the nerves which supply them also suffer. The 

 same is the case in regard to the nerves and organs of sense; for atrophy of the 



1 " Medico-Chirurgical Transactions," vol. xx. 



2 The Author has for some time had under his observation a case in which three males 

 of a family have progressively become affected, between the ages of 3 and 5 years, with 

 fatty degeneration of the muscles, which has proceeded in the most advanced case to the 

 almost complete obliteration of their normal structure. This change had been considered 

 by many eminent practitioners to be idiopathic, that is, to have its primary origin in the 

 muscular tissue ; and the measures which had been employed to arrest it had been of no 

 avail whatever. It was a strong argument, however, against such a view of the case, that, 

 in the heart of the eldest son, who died of fever at the age of 16, no fatty degeneration could 

 be discovered ; and on making inquiry into the history of the parents and their families, 

 ample evidence was discovered for the belief that the disease was dependent upon want 

 of functional power in the nervous centres. Acting on this view, it was recommended that 

 the muscular system should be kept as much as possible in a state of active exercise, and 

 that a weak galvanic current should be frequently transmitted through the limbs from the 

 spine. This treatment has proved so far successful, that the progress of the disease appears 

 to have been arrested in the most advanced case , whilst a decided improvement has taken 

 place in the condition of a younger child, who was previously passing rapidly into a state 

 resembling that of his elder brothers. 



