CHAP. XI.] FUNCTIONS OF THE ENCEPHALON. 341 



these limbs the molecular phenomena which characterize passive con- 

 traction continue. It must be remarked, however, that muscles 

 separated from their proper nervous connexion soon suffer in their 

 nutrition, from the want of that amount of exercise which is neces- 

 sary for it. For this important observation we are indebted to 

 Professor John Reid, who likewise called attention to the confir- 

 matory fact, that, in those palsies with which there is combined 

 more or less irritation of the nervous centre, the muscles do not suffer 

 in their nutrition, in consequence of the exercise they undergo in the 

 startings so frequently excited in them by the central irritation. 



After these remarks, it is scarcely necessary to add, that we must 

 enter our protest against the doctrine which assigns the spinal cord 

 as the source of muscular irritability. This doctrine, indeed, has but 

 slender support either in reason or experience. It is contrary to all 

 analogy to assign to one tissue the power of conferring vital pro- 

 perties on another. If bone, tendon, and cartilage have their dis- 

 tinctive properties, they possess them in virtue of some peculiarity 

 inherent in their mode of nutrition, and do not derive them from any 

 other texture. And, surely, it is too much to suppose that a tissue, 

 like muscle, so complex in its chemical constitution, and so exqui- 

 sitely organized for the development of its proper force, should be 

 dependent on the nervous system, or a portion of it, for its con- 

 tractile power! Our own experience is quite opposed to the 

 statement of Dr. Hall, that in cases of palsy dependent on cerebral 

 lesion, the muscles of the affected limbs acquire an increased 

 irritability, from the cord, which he supposes to be the source of 

 irritability, remaining intact, while the influence of the exhauster 

 of irritability (the brain) is removed. In all our experiments, 

 which have been numerous, we have found the palsied muscles less 

 excitable by the galvanic stimulus than those of the sound side, and 

 the difference has been more manifest the longer the period since 

 the paralytic seizure. Exceptions to this statement, however, are 

 found in those cases in which the paralysis has been accompanied 

 with cerebral irritation sufficient to keep up a state of more or less 

 active contraction of the affected muscles.* 



Functions of the Medulla Oblongata, Mesocephale, Corpora Striata, 

 and Optic Thalami. Although the anatomist may find it conve- 

 nient to describe these parts each by itself, it is impossible, in 

 the consideration of their functions, to separate them completely, 

 they are so closely connected with each other, and the functions of 



* See also Dr. Pereira's experiments, Mat. Med. vol. ii. p. 1301. 



