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1342. The place of the australopithecines in human evolution: grounds for doubt?
Although most studies emphasise the similarity of the australopithecines to modern man, and suggest, therefore, that these creatures were bipedal tool-makers at least one form of which (Australopithecus africanus--"Homo habilis", "Homo africanus") was almost directly ancestral to man, a series of multivariate statistical studies of various postcranial fragments suggests other conclusions. Their locomotion may not have been like that of modern man, and may, though including a form or forms of bipedality, have been different enough to allow marked abilities for climbing. Bipedality may have arisen more than once, the Australopithecinae displaying one or more experiments in bipedality that failed. The genus Homo may, in fact, be so ancient as to parallel entirely the genus Australopithecus thus denying the latter a direct place in the human lineage.
1346. How specific are nuclear "receptors" for thyroid hormones?
The presence of "high-affinity-saturable" binding sites for thyroid hormones of similar characteristics not only in isolated nuclei but in all the major extranuclear cellular components, as well as the failure of cytosol to promote nuclear binding, invalidates the analogy with steroid hormone receptors and necessitates a more critical assessment of the physiological relevance of current approaches to binding of thyroid hormone in vitro nuclear preparations.
1347. Form and function of cat retinal ganglion cells.
Recent explorations of the morphology of retinal neurones, combined with neurophysiological recordings have made it possible to link specific anatomical types with particular physiological classes. At the same time, the relatively complete anatomical mapping of the retina has revealed some bias in the sampling of neurones by electrophysiological techniques.
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