ON THE STRUCTURE AND FUNCTION OF THE MAMMALIAN HEART. 229 



culo-ventricular bundle) and the whole of the rest of the tissues 

 connecting the auricles to the ventricles have been severed. 



Impulses are capable of passing over the newly described path either 

 in the normal direction (auricle to ventricle), or in the reverse direction 

 (ventricle to auricle). The connection of auricle to ventricle being 

 through the tissue of the right lateral node, which presumably conducts 

 impulses at a slower rate than ordinary cardiac tissue, the pause may 

 reasonably be explained as being due to this circumstance. The pre- 

 sence of such an alternative path has to be reckoned with in putting 

 forward possible explanations of various anomalies of cardiac action. 



References. 



' Observations on the Auriculo-ventricalar Junction in the Mammalian 

 Heart,' Quart. Jour. Experimenial Physiology, vii. 2. 193. 



' The Structure of the Cardiac Tissues at the Auriculo-ventricular 

 Junction,' Proc. Pliijs. Soc. Nov. 1913. Jour. Pliys. xlvii. 4 and 5. 



" Sur le Systeme excitateur et conducteur du Owur,' Arch, des Mala- 

 dies du Cceiir. Paris. Jan. 1914. 



* The Right Lateral Auriculo-ventricular Junction of the Heart,' Proc. 

 Phys. Soc. March 1914. Jo2ir. Phys. xlviii. 2 and 3. 



' Some Problems in Cardiac Physiology,' B.M.J. July 18, 1914. 



' Illustrations of the Eight Lateral Auriculo-ventricular Junction in the 

 Heart,' Proc. Phys. Soc. June 1914. Jour. Phys. xlviii. .5. 



' A Conducting Path between the Eight Auricle and the External Wall 

 of the Right Ventricle in the Heart of the Mammal,' Proc. Phys. 

 Soc. June 1914. Jour. Phys. xlviii. 5. 



Part II. 



During the past year attention has been directed principally to the 

 working out of detail, and a considerable amount of material is 

 practically ready for publication. The most important new fact put on 

 record is perhaps that of the existence of considerable masses of muscle 

 in the auriculo-ventricular valves. This will necessitate a review of the 

 usual conception of the action of these structures. 



References. 



' On the Mechanism of the Cardiac Valves,' Proc. Royal Soc. B. 



vol. 88, 1915. 

 ' Illustrations of Muscular Tissue in the Auriculo-ventricular Valves of 



the Mammal's Heart,' Proc. Phys. Soc. July 3, 1915. 



The Committee ask to be reappointed, with a grant of 50?. 



The Renting of Cinchorw Botanic Station in Jamaica. — Report 

 of Committee, consisting of Professor F. 0. Bower (Chair- 

 man), Professor E. H. Yapp (Secretary), and Professors 

 E. BuLLER, P. W. Oliver, and F. E. Weiss. 



'The Committee for ' The Eenting of Cinchona Botanic Station in 

 • Jamaica ' report that since the last meeting of the British Association 



