Restored sand dune habitat at Cape Canaveral, Florida. To help prevent erosion, 180,000 shrubs, including grasses, sunflowers, vines, sea grapes, and saw palmettos, were planted. (Credit: Dan Casper/National Aeronautics and Space Administration)
Diagram of the apparatus for measuring the pigeon's absolute visual threshold. (After D S. Blough, A method for obtaining psychophysical thresholds from the pigeon, J. Exp. Anal. Behav., 1:31–43, 1958)
Transverse sections through the thallus of Marchantia. (a) Middle portion with scales and rhizoids on the underside. (b) Margin of the thallus more highly magnified. (After H. Kraemer, Applied and Economic Botany, 2d ed., Wiley, 1916)
Marchantia. (a) Example of male gametophyte (antheridial plant) (after H. J. Fuller and O. Tippo, College Botany, Holt, 1949). (b) Section through an antheridial receptacle (after W. J. Robbins and H. W. Rickett, Botany, 3d ed., Van Nostrand, 1939).
Marchantia. (a) Example of female gametophyte (archegonial plant) (after H. J. Fuller and O. Tippo, College Botany, Holt, 1949). (b) Section through an archegonial receptacle (after W. J. Robbins and H. W. Rickett, Botany, 3d ed., Van Nostrand,…