FINE STRUCTURAL CHANGES IN HEART MUSCLE IN RELATION TO THE LENGTH-TENSION CURVE

t The author wishes to acknowledge the technical assistance of Albert Vossler. l Abercrombie, M., Anat. Record, 94, 239 (1946). Abercrombie's formula: P = A X M/(L + M) (P = average number of nuclear points per section; A = crude count; M = thickness of section; L = particle size. Explanation: "Ideal points" would be found in only one tissue section each. Particles of finite size will be cut once or more depending on both their dimensions and the thickness of the sections. This represents a source of error in counting particles in tissue sections, which can be corrected with the above formula. 2 Braitenberg, V., and R. P. Atwood, J. Comp. Neuro., 109, 1 (1958). 3Ellis, R. S., J. Comp. Neuro., 32, 1 (1920). 4Elliott, K. A. G., J. Neurophys., 11, 437 (1948). 5 Fried, G. H., and S. R. Tipton, Proc. Soc. Exp. Bio. Med., 82, 531 (1953). 6 Friede, R. L., Acta Anat., 20, 290 (1954). 7Friede, R. L., Acta Anat., 25, 65 (1955). 8 Friede, R. L., A. M A. Arch. Neuro., 8, 67(1963). 9 Friede, R. L., and W. H. van Houten, these PROCEEDINGS, 48, 817 (1962). 10 Hawkins, A., and J. Olszewski, Science, 126, 76 (1957). 11 Jansen. J., and A Brodal, in Aspects of Cerebellar Anatomy (Oslo: Tanum, 1954). 12 Krebs, H. A., Biochem. Biophys. Acta, 4, 249 (1950). 3 Locker, A., and R. M. Kaps, Z. ges. exp. Med., 134, 29 (1960). 14 Spector, W. S., ed., Handbook of Biological Data (Philadelphia: Saunders, 1956). 15 Vernberg, F. J., Biol. Bull., 106, 360 (1954).