The dominance of maternal or of paternal characters in Echinoderm hybrids

D. H. Tennent
1910 Development, Genes and Evolution  
One of the most interesting and important problems connected with the results of Echinoderm hybridization is the determination of the factors influencing the appearance of maternal or of paternal characters in the hybrid embryo. VERNON (1898 VERNON ( , 1900 showed a seasonal variation and tried to show that the characters of the hybrid pluteus are dependent on the relative ripeness of the eggs and of the sperm used in the crosses. DONCASTER (1904) concluded, as a result of his experiments, that
more » ... s experiments, that the temperature of the water, in which the embryos develope, is the determining factor. HERBST (1906a HERBST ( , 1906bHERBST ( , 1907 in an extended and able series of papers, expressed his conviction that while temperature was a contributing factor, it was not the only one and showed that the dominance might be swung toward the maternal side by a combination of artificial parthenogenesis and fertilization. This paper deals with the identification of this additional factor. The experimental evidence upon which it is based shows that while the theories of the investigators mentioned are correct, they do not present the whole truth. The actual factor determining the dominance is directly concerned with differences of season and of temperature, but these two factors arc simply contributory. The factor determining the dominance is the variation in alkalinity of the sea water in which the embryos develope. Archiv f. Entwicklungsmechanik. XXIX. 1
doi:10.1007/bf02297061 fatcat:4bst2xhkmjexvnplnruyt2hd3i