The evidence just presented has shown that splanchnic stimulation improves the contraction of fatigued muscle. Splanchnic stimulation, however, has two effects--it increases general arterial pressure and it also causes a discharge of adrenin from the adrenal glands. The questions now arise--Does splanchnic stimulation produce the improvement in muscular contraction by increasing the arterial blood pressure and thereby flushing the laboring muscles with fresh blood? Or does the adrenin liberated by splanchnic stimulation act itself, specifically, to improve the muscular contraction? Or may the two factors coöperate? These questions will be dealt with in the next two chapters. REFERENCES [Footnote 70: Albanese: Archives Italiennes de Biologie, 1892, xvii, p. 243.] [Footnote 71: Boinet: Comptes rendus, Société de Biologie, 1895, xlvii, pp. 273, 498.] [Footnote 72: Oliver and Schäfer: Journal of Physiology, 1895, xviii, p. 263. See also Radwánska, Anzeiger der Akademie, Krakau, 1910, pp. 728-736. Reviewed in Zentralblatt für Biochemie und Biophysik, 1911, xi, p. 467.] [Footnote 73: Dessy and Grandis: Archives Italiennes de Biologie, 1904, xli, p. 231.] [Footnote 74: Panella: Archives Italiennes de Biologie, 1907, xlviii, p. 462.] [Footnote 75: Cannon and Nice: American Journal of Physiology, 1913, xxxii, p. 44.] [Footnote 76: Bowditch and Warren: Journal of Physiology, 1886, vii, p. 438.] [Footnote 77: Elliott: Journal of Physiology, 1912, xliv, p. 403.] [Footnote 78: Cannon and Lyman: American Journal of Physiology, 1913, xxxi, p. 376.] [Footnote 79: Young and Lehmann: Journal of Physiology, 1908, xxxvii, p. liv.] CHAPTER VII THE EFFECTS ON CONTRACTION OF FATIGUED MUSCLE OF VARYING THE ARTERIAL BLOOD PRESSURE