On Maps of the Moon. 1 25 



volition. The integrity of the cerebellum is necessary for the 

 regularity of acts of locomotion. While the brain is entire, the 

 animal will see, hear, and exhibit marked and decisive svm- 

 ptoms of volition ; but if the cerebellum be destroyed, he will 

 be unable to preserve the equilibrium requisite for the per- 

 formance of locomotion. Irritability will, however, subsist for 

 a considerable time in the remaining parts of the body, without 

 the intervention of the cereb7-um or cerebellum. Every irrita- 

 tion of a nerve produces action in the muscles to which it is 

 distributed: every irritation of the spinal marrow produces 

 action in the members and parts below the irritated point. 

 The faculty of propagating irritation on the one hand, and 

 receiving pain on the other, is altogether confined to the supe- 

 rior part of the medulla oblongata : viz. the part at which the 

 iubeicula quadrigemina adhere to it. This at least is the place 

 whither all sensations must arrive, in order to become percep- 

 tions : this is the place whence all the orders of the Will must 

 necessarily depart : hence the continuity of the nervous organ 

 from this place to the particular parts concerned, is necessary 

 for the execution of spontaneous motion, and for the percep- 

 tion of impressions whether internal or external. 



All these conclusions ai'e not identical with our author's, 

 nor conceived in the same terms ; but they are those which 

 have appeared to us to be rigorously deducible from the facts 

 he has so ably brought forward and attested : they are doubt- 

 less sufficient to enable you to judge of the importance of those 

 facts ; to engage you to express your satisfaction to the author 

 for what he has already done ; and to procure for him your 

 invitation to continue his communications in the progress of 

 his interesting inquiries. 



G. CuviER, of the Institute. 



N. B. This Report was adopted by the Royal Academy of 

 Sciences in its sitting of the 22d of July 1822. 



XXVIII. On Maps of the Moon. 

 To the Editors of the Philosophical Magazine and Journal. 



'T'HE want of an accurate and well-executed map of the 

 -^ moon must, I imagine, liave been felt by many persons 

 fond of astronomy, as well as by me. I have inquired at the 

 shops in London for a map of the moon, without success, al- 

 though planis|)heres of the stars and st)hn- systems are to be 

 had without dilliculty. In Keill's Astronomy, London, 1739, 



are. 



