Limb amputations, probably caused by amniotic constriction bands, were examined histologically in a 20 week human fetus to assess the degree of intrauterine healing. No acute inflammatory process, no removal of necrotic material, and no granulation tissue formation were seen at any of the amputation sites. A recent ulcer, probably caused by friction of an exposed piece of bone in the stump of the right leg, also showed no inflammatory response. Healing was by coagulation of exposed tissue and by a minor degree of mesenchymal proliferation without repair. Similar changes have been described in experimental intrauterine wound healing in rats, lambs, opossums and baboons. Conversion from a non-specific to a classical postnatal inflammatory response occurs sometime before term. It is not known at what point this change takes place in man; examination of this infant suggests that it occurs after the twentieth week of gestation.

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Hearts from 20 mammalian orders were examined according to a fixed protocol to determine if the gross differences of shape and internal anatomy could be explained. Three generalizations can be made: firstly differences are most closely related to taxonomic position, secondly some features, such as the prominence of the conus of the right ventricle in animals that leap, dig or sprint regularly as part of their defence mechanism and a long, narrow left ventricle in endurance performers may be more closely related to activity than ancestry, and lastly some characteristics may be pleiotropic effects of thoracic morphogenesis.

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