Abstract
Developmental and chromosomal aspects of giant digynic triploids were studied with three 4-cell embryos, one 8-cell embryo and one blastocyst. Without exception, they displayed normal development and a complete set of triploid chromosomal complements. Their mitotic activity was normal or even high when compared with their diploid sibs. The giant blastocyst had the largest number of blastomeres and metaphasic cells among eight blastocysts of the same batch. Suggestion is made that the triploids developing from giant oocytes are more favoured for preimplantation development than the triploids caused by any other mechanism.
