THE METABOLISM OF THE BODY. 471 
prehended, In that preventive medicine of the future to which 
we fondly look to advance the welfare of mankind, such consid- 
erations must largely enter. 
Tue INFLUENCE OF THE NERVOUS SYSTEM ON METABOLISM 
(NUTRITION). 
This subject is of the utmost importance, and has not re- 
ceived the attention hitherto, in works on physiology, to which 
we believe it is entitled, so that we must discuss it at some 
length. 
We may first mention a number of facts on which to base 
conclusions: 1. Section of the nerves of bones is said to be fol- 
lowed by a diminution of their constituents, indicating an 
alteration in their metabolism. 2. Section of the nerves sup- 
plying a cock’s comb interferes with the growth of that ap- 
pendage. 3. Section of the spermatic nerves is followed by de- 
generation of the testicle. 4. After injury to a nerve or its 
center in the brain or spinal cord, certain affections of the 
skin may appear in regions corresponding to the distribution 
of that nerve: thus, herpes zoster is an eruption that follows 
frequently the distribution of the intercostal nerve. 5. When 
the motor cells of the anterior horn of the spinal cord or cer- 
tain cells in the pons, medulla, or crus cerebri are disordered, 
there is a form of muscular atrophy which has been termed 
“active,” inasmuch as the muscle does not waste merely, but 
the dwindling is accompanied by proliferation of the muscle 
nuclei. 6. In acute decubitus bed-sores form within a few hours 
or.days of the appearance of the cerebral or spinal lesion, and 
this with every precaution to prevent pressure or the other 
conditions that favor the formation of such sores. 7%. After 
section of both vagi, death results after a period, varying in 
time, as do also the symptoms, with the animal. In some ani- 
mals pneumonia seems to account for death, since it is found 
that, if this disease be prevented, life may, at all events, be 
greatly prolonged. The pneumonia has been attributed to 
paralyses of the muscles of the larynx, together with loss of 
sensibility of the larynx, trachea, bronchi, and the lungs, so 
that the glottis is not closed during deglutition, and the food, 
finding its way into the lungs, has excited the disease by irrita- 
tion. The possibility of vaso-motor changes is not to be over- 
looked. In birds, death may be subsequent to pneumonia or 
to inanition from paralysis of the cesophagus, food not being 
