American journal of physiology . physiology, 1899, xxiv,PP- 51-71; WoODWORTH: This journal, 1899,iii, pp. 26-44. Mammalian Smooth Mtiscle.— The Cats Bladder. 201 first relaxation on tvarming, although at low temperatures they arefeeble and very slow. As the temperature rises toward that of thebody, the contractions become more frequent and are of greaterextent. Beyond a maximum slightly below body temperature,further warming increases the rapidity and frequency of the move-ments, but diminishes their amplitude, until they disappear entirelywith the loss of irritability at a temperature in the
American journal of physiology . physiology, 1899, xxiv,PP- 51-71; WoODWORTH: This journal, 1899,iii, pp. 26-44. Mammalian Smooth Mtiscle.— The Cats Bladder. 201 first relaxation on tvarming, although at low temperatures they arefeeble and very slow. As the temperature rises toward that of thebody, the contractions become more frequent and are of greaterextent. Beyond a maximum slightly below body temperature,further warming increases the rapidity and frequency of the move-ments, but diminishes their amplitude, until they disappear entirelywith the loss of irritability at a temperature in the neighborhood of55° C. Where automatic contractions are present in the preparation,irregularities in the course of the tonus curve are introduced. Thisis the case in the record shown in Fig. 12. With the appearance ofspontaneous activity the curve, instead of falling regularly to 40° C,as in the dotted line, shows a secondary rise. This is due to the factthat in such a condition some part of the bladder is always in contrac-. 39 41 43 4S 47 49 51 53 55SS e? 19 31 3a 3S 35 37 3S 40 4B 44 46 48 SO SS 54 SS Figure 13. — Curve of change of tone with rising temperature, showing the variationproduced by frequent stimulation. One-third the original size. tion, the result being an apparent rise in tone which increases with theamplitude of the movements. And again, on raising the temperaturebeyond 40 C, when the contractions so diminish in amplitude thatthey no longer of themselves sustain the lever, there is an apparentsecondary loss of tone. This form of curve is characteristic of suchpreparations, and in other respects is perfectly in accordance with theresult shown in Fig. 11. Fig. 12 shows also the loss of tone follow-ing the rise to 54° C, and the true contraction of heat rigor, appear-ing at 69° C. If the muscle be stimulated during the course of an experiment onthe influence of temperature on the tone of the muscle, another char-acteristic variation from the true result i
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