Zoological Society. 71 



but from this notice it would scarcely have been anticipated that so 

 large a collection was made as was found in the present instance. 

 The dilatation had a rounded appearance ; distended the skin so 

 as to show distinctly and widely separated the insertion of each of 

 the small feathers at this part ; and measured in length 1 1 lines, 

 and in depth 6. On opening the pouch it proved to be simple, and 

 unconnected except with the cavity of the mouth. 



Mr. Heming also exhibited a drawing taken from the recent bird. 



Dr. Marshall Hall showed some experiments in the decapitated 

 Turtle. Irritation of the nostrils, larynx, and spinal marrow induced 

 acts of inspiration ; that of the fins and tail induced movements of 

 the other parts respectively. 



But the principal object of Dr. Hall was to show that irritation 

 of the nerves themselves equally induced movements of the limbs, 

 &c. When either the sentient or the motory branch of the lateral 

 spinal nerves was stimulated, motions were induced in all the limbs. 

 Dr. Hall stated that a movement of inspiration and of deglutition 

 was caused in the Donkey by irritation of the eighth pair of nerves. 

 It has been already stated that irritation of the nostrils, or the 

 branches of the fifth pair of nerves, induced inspiratory acts in the 

 Turtle. From these and other facts. Dr. Hall is induced to consider 

 the functions of these two nerves as similar. He further observed 

 that both are nerves of secretion, and that both are muscular nerves 

 — if the minor portion of the fifth be included — as well as exciters 

 of respiration : the fifth differs chiefly in being sentient, being dis- 

 tributed to external as well as internal surfaces. With the fifth and 

 eighth. Dr. Hall associates other spinal nerves. He considers re- 

 spiration as a part of a general function of the nen'^ous system, 

 which presides over the larynx, pharynx, sphincters, ejaculators, &c., 

 to which he has given the name of reflex, from its consisting of im- 

 pressions carried to and from the medulla oblongata and medulla 

 spinalis. Some illustrations of this function were given by Dr. Hall 

 at the Meeting of the Committee of Science and Correspondence on 

 November 27, 1832, (Lond. and Edinb. Phil. Mag. vol. ii. p. 477,) and 

 further illustrations of it have formed the subject of a Paper by him, 

 which has since been published in the ' Philosophical Transactions'. 

 7'he experiments shown on the present occasion demonstrate the 

 existence of a series of physiological facts at variance with the law 

 laid down by M. Miiller in his Paper entitled " Nouvelles Experi- 

 ences sur I'eff^et que produit 1' Irritation mecanique et galvanique sur 

 les racines des nerfs spinaux ; par Jean Miiller, Professeur a I'Uni- 

 versite de Bonn," and published in the * Annales des Sciences Na- 

 turelles, ' tom. xxiii. (1831), p. 95, viz. " II suit encore qu'il y a 

 des nerfs qui n'ont point de force motrice ou tonique, qui ne peuvent 

 jamais occasionner des mouvemens par eux-meraes, qu'ils soient ir- 

 rites par Taction galvanique ou mecanique, et qui ne conduisent le 

 courant galvanique que passivement, comme toutes les parties molles 

 humides ; qu'il y a en revanche des nerfs moteurs ou toniques (nervi 

 motorii seu tonici) qui montrent ^ chaque irritation mediate ou im- 

 mediate leur force tonique, qui agit toujours dans la direction des 



