11. Small pollen (sp2) and l8 are probably between g1 and li with the order li-sp2-l8-g1-R. Plants trisomic for chrom 10. and having the constitution Sp2 Sp2 sp2 had about 20% small pollen (sp2) and about 80% normal pollen. This indicates that n+1 pollen of Sp2 sp2 constitution is of normal size and that sp2 is recessive to Sp2 in such gametophytes.