. Carnegie Institution of Washington publication. 246 The Mechanism of Evolution in Leptinotaksa showing simple gametic composition. In this pair of biotype 1 blacks from nature were mated and gave in F^ biotype 1, biotype 2, and biotype 6. The F^ blacks when inbred gave, out of 7 pairs, 4 that came true and 3 that gave blacks and type 2. In F3 and F^ the pnre-breeding blacks continued to breed true and the type 2 was heterozygous, giving type 2 and blacks of biotype 1, the latter breeding true. Of the biotype 6, which appeared in F^, 2 pairs out of 8 gave progeny, and these came true to type
. Carnegie Institution of Washington publication. 246 The Mechanism of Evolution in Leptinotaksa showing simple gametic composition. In this pair of biotype 1 blacks from nature were mated and gave in F^ biotype 1, biotype 2, and biotype 6. The F^ blacks when inbred gave, out of 7 pairs, 4 that came true and 3 that gave blacks and type 2. In F3 and F^ the pnre-breeding blacks continued to breed true and the type 2 was heterozygous, giving type 2 and blacks of biotype 1, the latter breeding true. Of the biotype 6, which appeared in F^, 2 pairs out of 8 gave progeny, and these came true to type in Fo, F3, and F4. The biotype 2 in F^ inbred gave biotype 1 and biotype 2 in Fj, but these were not mated for further testing. The simple behavior of this pair shows a relatively simple gametic com- position and the capacity for extracting pure-breeding biotypic races by the mating of likes. F8 Ft Fa F5 F4 •Fs •Pz Fi ^ m ^ mm ^. lE"b ^ m "C'a lC1_-C" Fig. 39.—Showing results obtained from a single breeding pair of L. multitCBiiiata from the Chapultepec colony of biotype 4. Even more simple cases have been found where blacks of biotype 1 were pure homozygotes, but in nature these are not common, but may be found in almost any population of emerging stock by testing enough samples. It is certain, therefore, that as regards this biotype that it exists in nature in all degrees of gametic constitution from pure homozygous to highly complex and intricately involved heterozygous constitutions, where there are correlations with other char- acters, giving extreme diversity in the progeny of a single pair. These correla- tions, while of importance in the production of diversity in the pronotal char- acter in the population, can not be discussed in this part of the paper. The conditions found in the biotype 1 pattern are equally true of any of the others found in the entire population. In figure 39 are shown the results. Please note that these images are extracted fr
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