xiv CONTENTS. 



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 



126. 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 neYves. 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 



