412 Wnltor J. Moek. 



BIBLIOGRAPHY. 



Carlson, A. J., 1904. The Nervous Origin of the Heart-beat in Limulus and 

 the Nervous Nature of Coordination or Conduction in the Heart. 

 Am. Jour. Phys., Vol. XII, p. 67. 



Heidenhain, 1901. Ueber die Struetur des meusoblichen Herzmuskels. An. 



Anz., Vol. XX, p. 33. 

 MaCallum, 1897. On the Histology and the Histogenesis of the Heart 



Muscle Cell. An. Anz., Vol. XII, p. 609. 

 Mabceau, 1904. Recherches sur la structure et le developpement compare 



des fibres cardiaque. Ann. des Sc. Nat. Zool., Vol. XIX, p. 245. 

 Patten and Redebaugh, 1899. Studies on Limulus. Jour. Morph., Vol. XVI, 



p. 129. 

 Renaut et Mollabd, 1904. Le Myocard. Rev. Gen. d'Hist., Vol. I, p. 213. 



EXPLANATION OF PI^TE I. 



Fig. 1. Semi-diagrammatic portion of entire heart wall, a — branching 

 muscular layer, b — Basement membrane, c — Elastic tissue. 



Fig. 2. Trabeculre teased in 20 per cent nitric acid. Drawn with camera 

 lucida. Leitz Ob. 0, Oc. 4. a — Blunt end of small strand. 



Fig. 3. Large flat trabecula. Teased from 20 per cent nitric acid and 

 drawn under camera lucida as above. 



Fig. 4. Semi-diagrammatic. Constructed from thick paraffin section. 

 Anastomosing trabeculfe are shown with anastomosing strands of muscle 

 within, a — Sheath around triibeculte. B — Strand of contractile tissue, d — 

 Nucleus of contractile strand, c — Nucleus of sheath. 



