Abstract
LONDON Royal Society, Feb. 25.—D. M. Needham, J. Needham, E. Baldwin, and J. Yudkin: A comparative study of the phosphagens, with some remarks on the origin of vertebrates. Arginine phosphate exists in all the invertebrate phyla of which representatives were studied, though in the coelenterates it was only found in a ctenophore. This compound may be associated with ciliary as well as muscular movement. Creatine phosphate is not confined to the vertebrates, but was found in echinoderm jaw muscle and entero-pneust tissues. If any evolutionary significance may be attached to these findings, it is probable that they support the echmoderm-enteropneust theory of vertebrate descent (Bateson: MacBride: Garstang).—G. Phillips: Myotatic reflexes in sympathectomised muscle. After excision of its sympathetic innervation, skeletal muscle exhibits quantitative changes in proprioceptive reflex activity. Simultaneous myotatic contractions of two soleus muscles when subjected to the same passive stretch have been recorded by a ‘double’ isometric myograph and a twin string galvanometer. Three conditions of stretch-stimulation have been regarded as essential in making comparable records. These are, a small passive increment of length, performed at an even rate, from an initial posture of minimal tension. Under such conditions the latent period of the myotatic reflex determined by the time of onset of the first action current wave is shorter in the sympathectomised muscle. Soleus muscle deprived of its sympathetic innervation some weeks previously loses in great degree its power of maintenance of any postural contraction of other than low tension. The available evidence denies the existence of any sympathetic nervous mechanism responsible for the direct qualitative control of postural reactions; and suggests quantitative changes following sympathectomy are produced by a disturbance of the excitability of proprioceptive end-organs in sympathectomised muscle.—J. C. Eccles and H. E. Hoff: The rhythmic discharge of motoneurones. The events during the rhythmic cycle are described in terms of the ‘activity’ of the rhythmic centre, by which is meant the propensity of the rhythmic centre to set up a reflex discharge.
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Societies and Academies. Nature 129, 373–375 (1932). https://doi.org/10.1038/129373a0
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DOI: https://doi.org/10.1038/129373a0