xiv CONTENTS. 



PAGE 



§ 123. The characters of the pulse curve ; influence of pressure exerted by 



lever 226 



§ 124. The changes undergone by the pulse wave along the arterial tract 227 



§ 125. The velocity of the pulse wave 228 



§120. The length of the pulse wave 229 



§ 127. Secondary waves. Katacrotic and anacrotic tracings . . . 230 



§ 128. The dicrotic wave : its causes 232 



§ 129. Circumstances determining the prominence of the dicrotic wave . 234 



§ 130. The predicrotic wave. Anacrotic waves 235 



§ 131. Venous pulse 236 



SECTION V. 



The Regulation and Adaptation of the Vascular Mechanism. 



The Regulation of the Beat of the Heart. 



§ 132. The two great regulators ; changes in the heart beat and changes 



in the peripheral mechanism 238 



The Development of the Normal Beat. 



§ 133. Graphic record of the heart beat. The beat of the frog's heart. 

 The sequence of events, and the descending scale of rhythmic 

 power 239 



§ 134. Some features of the heart beat in the mammal .... 244 



The Government of the Heart Beat by the Nervous System. 



§ 135. Inhibition in the frog by stimulation of vagus nerves. Features 



of inhibition 244 



§ 136. Augmentation of the heart beat in the frog. Antagonism of aug- 

 mentation and inhibition. Course of augmentor fibres in the 

 frog 246 



§ 137. Reflex inhibition. Cardio-inhibitory centre 249 



§ 138. Inhibition in the mammal ; effect on blood pressure. Reflex inhi- 

 bition. Course of augmentor fibres in the dog .... 250 



§ 139. Action of atropin and muscarin 257 



Other Influences regulating or modifying the Beat of the Heart. 



§ 140. Influences of blood, and substances contained in the blood. Influ- 

 ence of the distension of the cavities. Relation of heart beat to 

 blood pressure 258 



SECTION VI. 



Changes in the Calibre of the Minute Arteries. Vaso-motor 



Actions. 



§ 141. Changes of calibre in arteries as seen in the web of a frog's foot 



and elsewhere. Vaso-motor nerves 262 



§ 142. The vascular phenomena in a rabbit's ear 263 



