70 EUSKIN M. LHAMON 



CONCLUSIONS 



1. In hearts of beef, calf and sheep there is a definite connective 

 tissue sheath surrounding the sino-ventricular bundle, which com- 

 pletely invests and isolates that bundle from the heart muscle. 



2. The existence of this sheath can be demonstrated in its 

 entirety by injections, for the sheath is capable of maintaining 

 its integrity against considerable pressure from within. 



3. This sheath begins above where the fasciculi of the bundle 

 are continuous with the musculature of the interauricular septum 

 (Tawara's 'Knoten') and clothes the system up to its ventricular 

 termination, i.e., to its transition into cardiac muscle fibers. 



4. The sheath does not simulate a bursa, save very remotely, 

 perhaps, nor is it part of the lymphatic system of the heart. 



5. Hence this sheath is not a bursa and no synovial bursa 

 exists, for if a bursa be present in any portion, these injections 

 show that it is coextensive with the bundle itself. 



BIBLIOGRAPHY 



Curran, E. J. 1909 A constant bursa in relation with the bundle of His; with 

 studies of the auricular connections of the bundle. Anat. Rec, vol. 

 3, no. 12. 



De Witt, Lydia M. 1909 Observations on the sino-ventricular connecting sys- 

 tem of the mammalian heart. Anat. Rec, vol. 3, no. 9 



Dogiel, J. 1910 Die Bedingungen der automatischen-rhythmischen Herzkon- 

 traktion. Pfliigers Archiv., vol. 135. 



Fahr 1907 Uber die Moskulose Verbindung zwischen Vorhof und Ventrikel 

 (das Hissche Biindel) im normalen Herzen und beim Adams — Stokes 

 Symptom-komplex. Virch, Archi. f. Path. Anat., Bd. 188. 

 1908 Zur Frage der Atrioventrikularen Muskelverbindung in Herzen. 

 Verh. deutsch pathol Ges. 12. 



Keith and Flack 1907 Form and nature of the muscular connections between 

 the primary divisions of the vertebrate heart. Jour. Anat. and Phys. 

 London, vol. 41. 



Kent, Stanley 1893 Researches on the structure and function of the mamma- 

 lian heart. Journal of Physiology, vol. 14. 



Monckeberg, J. G. 1908a Uber den sogennanten abnormen Sehnenfaden in 

 linken Ventrikel des menschlichen Herzens und ihre Beziehungen zum 

 Atrio-ventrikularbundel. Verh. deutsch pathol. Ges. 12. 

 1908b Untersuchungen uber das Atrioventrikular-bundel im mensch- 

 lichen Herzen. Gustav Fischer. Jena. 



Retzer, Robert 1908 Some results of recent investigation on the mammalian 

 heart. Anat. Rec, vol. 2, no. 4. 



Tawara, S. 1906 Das Reizleitimgssystem des Sangetierherzens. Gustav 

 Fischer. Jena. 



