(1) The whole explanation fails unless some added agency be devised to take over the duty which the specific allelomorphic forces abandon after the occurrence of crossing over.(2) The conception of Species, however we may formulate it, can hardly be supposed to attach to allelomorphic or analytical varieties.(3) Most of our discussions center around a simple case in which the loci are modeled as diploid with two possible allelomorphs .(4) The allelomorphic classes shown at all loci from these samples were used as standards of comparison for the rest of the material.(5) ‘Heterozygous’ means having two different allelomorphs in the two corresponding loci of a pair of chromosomes.(6) We do not know at the moment what processes are primarily affected by the allelomorphs .(7) It was 25 years before these groups were shown to be inherited as Mendelian characters by means of three allelomorphic genes A, B and O and were, in fact, entities of one blood group system.(8) By this we mean that a certain total number of distinctive genes or allelomorphic factors constitute the complexity of the many kinds of plants and animals.