ENCEPHALIC SEAT OF MUSCULAR MOTION. 395 



that disease, confined to one hemisphere of the brain, or cerebellum, 

 and to one side of the mesial plane in the tuber annulare, constantly 

 affects the opposite side ; whilst disease, confined to one of the lateral 

 columns of the medulla oblongata and medulla spinalis, affects the 

 corresponding side of the muscular system ; the encephalon having 

 a crossed, the medulla a direct effect. 1 The crossing of the fibres at 

 the anterior surface of the marrow would not, however, account for 

 the loss of sensation in hemiplegia. Mr. Hilton 2 has examined care- 

 fully the continuation upwards of the anterior and posterior columns 

 of the spinal marrow into the medulla oblongata, and found, that the 

 decussation at the upper part of the marrow belongs in part to the 

 column for motion, and in part to the column for sensation; and 

 farther, that the decussation is only partial with respect to either of 

 the columns. 



The result of the examination of morbid cases has induced some 

 physiologists to proceed still farther in their location of the encephalic 

 organs of muscular motion ; and to attempt an explanation of para- 

 plegia, or cases in which one half the body, under the transverse bi- 

 section, is paralyzed. MM. Serres, Foville, and Pinel Grand-Champ 

 assert, that the anterior radiated portion of the corpora striata presides 

 over the movements of the lower limbs ; and the optic thalami over 

 those of the upper ; and that according as the extravasation of blood, 

 in a case of apoplexy, occurs in one of these parts, or in all, the para- 

 lysis is confined to the lower or to the upper limbs, or extends over the 

 whole body. In 1768, M. Saucerotte 3 presented a prize memoir to 

 the Academic Royale de Chirurgie, of Paris, in which a similar view 

 was expressed. He had concluded, from experiments, that affections 

 of the anterior parts of the encephalon paralyse the lower limbs, whilst 

 those of the posterior parts paralyse the upper. M. Chopart, in a 

 prize essay, crowned in 1769, and contained in the same volume with 

 the last refers to the results of experiments by M. Petit, of Namur, 

 which appeared to show, that paralysis of the opposite half of the 

 body was not induced by injury of the cerebral hemisphere, unless the 

 corpora striata were cut or removed. The experiments by Saucerotte 

 were repeated by M. Foville, and are detailed in a memoir, crowned 

 by the Academie Royale de Medecine, of Paris, in 1826. They were 

 attended with like results. In cats and rabbits, he cauterized, in some, 

 the anterior part of the encephalon ; in others, the posterior : in every 

 one of the former, paralysis of the posterior, and in the latter, of 

 the anterior extremities succeeded. Having in one animal mutilated 

 the whole of the right hemisphere, and only the anterior part of the 

 left, he found that the animal was paralysed in the hinder extremities, 

 and in the paw of the left fore-leg; but that the paw of the right re- 

 mained active. 4 



1 Lectures on the Nervous System and its Diseases, by Marshall Hall, M.D., &c., Lond., 

 1836, p. 34, or Amer. edit., Philacl., 1836. 



2 Proceedings of the Royal Society, No. 34, for 1837-8; also, Solly on the Brain, p. 145, 

 Lond., 1836; and Dr. John Reid, Edinb Med. and Surg. Journ., Jan., 1841, p. 12. 



3 Prix de 1'Academie Royale de Chirurgie, vol. iv. p. 373, Paris, 1819. 



4 Adelon, Physiologic de 1'Homme, edit, cit., ii. 44. 



