TROPHIC CENTRES AND NERVES, SO CALLED. 443 



observed cases of disease have shown, after disorganization 

 of cells belonging to what we recognize as motor centres. 

 As regards the latter condition, there can be no doubt of 

 the fact that progressive muscular atrophy is attended with 

 disorganization of certain of the motor cells of the spinal 

 cord. 



Without fully discussing this subject, which belongs to 

 pathology, the facts may be briefly stated as follows : We 

 may have progressive atrophy of certain muscles, which may 

 be uncomplicated with paralysis, except in so far as there is 

 weakness of these muscles, due to partial and progressive de- 

 struction of their contractile elements. The only pathologi- 

 cal condition in these cases, aside from the changes in the 

 muscular tissue, is destruction of certain cells in the antero- 

 latcral portions of the cord, with more or less atrophy of 

 the corresponding anterior roots. To one has pretended to 

 have demonstrated cells in the cord, presenting anatomical 

 peculiarities by which they may be distinguished from the 

 ordinary motor or sensory elements, but the fact of the de- 

 generation of certain cells, others remaining normal, and 

 this fact alone, has led to the distinction, by certain writers, 

 of trophic cells ; and, of course, these must be connected 

 with the muscles by trophic nerves. 1 



"We shall now study the phenomena of progressive mus- 

 cular atrophy from a physiological point of view, and see if 

 they afford any positive evidence of the existence of special 



1 Cases of progressive muscular atrophy have recently been studied with 

 great minuteness, and connected with lesions of certain cells in the cord, by 

 various authors ; among whom may be mentioned, Hayem (Xote sur vn cas 

 (tairopliie musculaire progressive avec lesions de la modle. Archives de physiologic, 

 Paris, 1869, tome ii., pp. 263, 391); Charcot and Joffroy (Deux can d'atrophie 

 muzcidaire progressive avec lesions de la substance prise et dcs faiweaux anfero- 

 lateral de la moefle epinere. Ibid., pp. 354, 629, 744) ; and Duchenne and Jof- 

 froy (De Vatrophie aigue et chronique des cellules nerveuses de la moelle et du bulbe 

 rachidien. Ibid., 1870, tome iii., p. 499). 



For a full account of the disease in question, with its relations to the degen- 

 eration of nerve-cells, the reader is referred to HAMMOND, Diseases of the Nerrov* 

 System, New York, 1871 p. 663, et *eq. 



