| Abstrakt: |
Interest in the developmental basis of symmetry and asymmetry, as old as experimental embryology itself, has recently become reactivated. A brief survey is made of recent or current activities in the following areas: (i) development of asymmetry in the chick limb bud, as related to the so-called zone of polarizing activity (Saunders et al.); (ii) in amphibians, as induced by transplantation and defect experiments, radiation, and chemical treatment (von Woellwarth, von Kraft, Wehrmaker); (iii) in mammals as related to (a) twinning (Cockayne, Torgerson, Baker-Cohen); (b) genetics (Feldman, Cockayne, Torgerson for man, Tihen et al., Hummel and Chapman for mouse); and (c) teratogens (Layton and associates); (iv) ultrastructure in snails (Morrill and Perkins); (v) asymmetry developing as a result of changes in chemical instability in homogeneous systems (Ortoleva and Ross); (vi) asymmetrical mentality (Sperry and associates). No general conclusions are attempted. [ABSTRACT FROM PUBLISHER] |
