104 



I then take away the sternum and divide the two diaphragmatic 

 nerves. The movement of the diaphragm, nevertheless, continues, 

 and it exists rhythmically together with the movements of the 

 other respiratory muscles. Six, eight or ten minutes afterwards 

 the movements of the diaphragm are still regular, (there are from 

 five to twenty contractions in a minute ;) the intercostal muscles 

 present then only partial contractions. The different bundles of 

 fibres of these muscles contract separately one after the other, 

 but the same bundle has generally regular contractions and re- 

 laxations. At that time I destroy the spinal cord, and see that 

 the movements of the diaphragm and of the intercostal muscles 

 are not changed after this operation ; they last for nearly a quar- 

 ter of an hour, and in some cases much longer ; their regularity 

 subsists. In the diaphragm, long after the general movement 

 has stopped, there are regular or irregular contractions of 

 many bundles of fibres for one, two, three hours, and sometimes 

 more. 



3. Deviation of limbs produced by a contraction of paralysed 

 muscles. In pigeons, after the destruction of all the lumbar part 

 of the spinal cord, the two posterior limbs are completely para- 

 lysed. The muscles then are soft, and the different parts of the 

 limbs do not resist at all, when we try to put them in flexion or in 

 extension. But after a few days the paralysed muscles become 

 harder, and after a few weeks there is an evident state of con- 

 traction in them. The limb is generally kept in a state of exten- 

 sion, and deviated on one side or the other. The deviation 

 becomes considerable after some months. 



Very likely it is owing to the same cause that club-foot and 

 other deviations are produced in embryos, after a destruction or 

 an absence of development of the spinal cord. 



4. Rhythmical movements in the eye of the Ink-fish. (Loligo 

 sepia, L.) The ciliary muscle so well described by Dr. W. Clay 

 Wallace, of New York, in the eyes of superior animals, is strongly 

 developed in the ink-fish. After an eye of this mollusc has been 

 separated from the body, I have sometimes found very singular 

 and perfectly rhythmical movements produced by the ciliary 

 muscle. These movements consisted in alternative contractions 

 and relaxations of some parts of that muscle. At every contrac- 

 tion a notable depression was produced in one portion of a zone 



