mutual sterility of blue and red flowers of the pimpernel, ii. [190];
supposed rules of transmission in crossing plants, ii. [68];
on crossing plants, ii. [98], [127], [130], [131];
on repeated crossing, ii. [267];
absorption of one species by another, when crossed, ii. [88];
crossing of varieties of the pea, i. 397;
crossing maize, ii. [105];
crossing of species of Verbascum, ii. [93], [105];
reversion in hybrids, ii. [36], [49], [50];
of Cereus, i. 392;