It was always understood that plants and animals, though completely contrasted in their higher representatives, approached each other very closely in their lower and simpler forms. But they were believed not to blend.
Asa GrayIndeed upon much that may have to say, I expect rather the charitable judgment than the full assent of those whose approbation I could most wish to win.
Asa GrayThis view, as a rounded whole and in all its essential elements, has very recently disappeared from science. It died a royal death with Agassiz.
Asa GrayThe best opinion now is, that there are multitudinous forms which are not sufficiently differentiated to be distinctively either plant or animal, while, as respects ordinary plants and animals, the difficulty of laying down a definition has become far greater than ever before.
Asa Gray