CONTENTS. xv 



PAGE 



155. The causes of the spontaneous rhythmic beat; the relations of the 



ganglia ; the features of the cardiac tissue 284 



156. The cardiac tissue and not the ganglia chiefly concerned in the 



maintenance of the sequence of events 288 



The Government of the Heart-Beat by the Nervous System. 



157. Inhibition in the frog by stimulation of vagus nerves. Features of 



inhibition 290 



158. Augmentation of the heart-beat. Antagonism of augmentation and 



inhibition. Course of augrneutor fibres in the frog . . . 292 



159. Eeflex inhibition. Cardio-inhibitory centre 295 



160. Inhibition in the mammal; effect on blood-pressure. Course of aug- 



mentor fibres in the dog 296 



161. Nature of augmentor and inhibitory effects. Action of atropin and 



rnuscarm 300 



Other Influences regulating or modifying the Beat of the Heart. 



162. Influences of blood, and substances contained in the blood. Influence 

 of the distension of the cavities. Relation of heart-beat to blood- 

 pressure 303 



SECTION VI. 



CHANGES IN THE CALIBRE OF THE MINUTE ARTERIES. VASO-MOTOR 



ACTIONS. 



163. Changes of calibre in arteries as seen in the web of a frog's foot and 



elsewhere. Vaso-motor nerves 306 



164. The vascular phenomena in a rabbit's ear . . . 307 



165. The effects on the vessels of the ear of dividing and stimulating 



the cervical sympathetic nerve . 



166. Course of vaso-motor fibres of the ear . . 309 



167. The effects on the vessels of the submaxillary gland of stimulating 

 the chorda tympani nerve; vaso-constrictor and vaso-dilator 



fibres 310 



168. Vaso-motor nerves of other parts of the body. Constrictor and 



dilator fibres in the sciatic and brachial nerves 313 



The Course of Vaso-constrictor and Vaso-dilator fibres. 



169. Course of vaso-constrictor fibres . . 317 



170. Course of vaso-dilator fibres 



The Effects, of Vaso-motor actions. 



171. Local and general effects of the constriction and dilation of an 

 artery or set of arteries 



Vaso-motor Functions of the Central Nervous System. 



172. Vaso-dilator fibres usually employed as part of a reflex action . 321 



173. Loss of tone resulting from the division of the spinal cord at various 

 levels. Vaso-motor centre in the medulla oblongata 



