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303
6. The roses of the types 1—3 showing all the chromosomes
in paired condition in the diakinesis have no doubt exclusively
sexual reproduction. At any rate there are no reasons for not
assuming that.
7. Triploid roses (type 4) showing in the heterotype division 7
paired and 7 single chromosomes may be interpreted as hybrids
derived from two such sexual forms possessing respectively 7 and
14 chromosomes in their germ cells. The reduction division in
the pollen mother cell is in quite accordance with the hybrid-
scheme of Drosera. To this group belong two bushes of chinensis
(indica) from Kew, gallica x cinnamomea (»turbinala» from Kew),
acicularis X cinnamomea (from Uppsala), blanda x pendulina (Uppsala);
and centifolia major hort.
8. One, perhaps more, of the bushes representing the type 8
showing 14 bivalent and 7 single chromosomes in the diakinesis
can in the same way be explained as a hybrid originated from
normal sexual parents, the one diploid, the other hexaploid. The
bush in question (»U. 31» in Hortus Bergianus, Stockholm) is stated
to be a hybrid of pendulina (and acicularis or nutkana). This form,
loo, realizes the reduction division in accordance with the Drosera-
scheme. In some anthers the pollen mother cells carry out a third
division after the homotypic. To the same type (8) belong three
other investigated forms, brilzensis, a native of Kurdistan, one
variety of damascena, and one specimen ot involuta. These forms
are to be discussed in the detailed publication.
9. All the examined form belonging to the section Caninae in
the widest sense (see point 2), i. e. most of the roses distributed
in Europe, North Africa and West Asia, are characterized by the
occurrence of both bivalent and single chromosomes in the hetero-
type division. They constitute the types 5—7 in the chromosome
lable and have then 7 paired and 14 or 21 or 28 single chromo-
somes. The forms of villosa (among them pomifera) and rubrifolia
have 7 paired plus 14 single = 28 chromosomes. All the forms
belonging to the old complex species canina, dumetorum, glauca
and coriifolia are pentaploid: 7 paired plus 21 single = 35 chro-
mosomes (about 30 investigated forms) The same chromosome
combination characterizes also certain forms of stylosa, the exami-
ned forms of tomentosa, and several species of the subseclion
Rubiginosae, for instance rubiginosa, Seraphini, sylvicola, micrantha,
nilidula, sicula, hungarica, and certain forms of glutinosa. I suppose
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