1916] DEV RIES—DIMORPHIC MUTANTS* 277 
of rosettes. Of the remaining 54, about one-half or 25 have 
flowered, the others reaching this stage approximately at the time 
when they were pulled up and counted. One plant was a mutant, 
being a metaclinous velutina, just as described in my book on 
pp. 308-311. The others were densa and laxa, as should be expected, 
and agreeing with these types throughout their whole life. 
O. canaXO. Cockerelli—A culture of 63 specimens embracing 
4 cana, 5 laeta, and 15 velutina, which have flowered, and a large 
number of rosettes of radical leaves. Two plants were mutants 
of the type of O. lata and one of them has flowered. Neither in 
the rosette stage nor at the time of flowering have the plants of 
the cana type showed any difference from ordinary O. cana, the char- 
acters of the father, also of its twin hybrid type, being invisible 
in them. Such was the case in almost all the beds containing 
the hybrids whose mother was cana, and this made the distin- 
guishing and counting of this type quite easy and sharply defined, 
and therefore fully reliable. Short narrow leaves of a gray color, 
a slender spike with long, thin flower buds with nodding tips were 
everywhere the same distinguishing marks. The /aeta and velutina 
had the ordinary type of these twins, as produced by O. Cockerelli. 
The reciprocal cross yielded 19 annual and 13 biennial /aeta, 
besides 4 annual and 23 biennial velutina of the same type. The 
annual plants have flowered; the biennials became stout rosettes 
in July and August. 
O. canaXO. Hookeri.—Represented by 25 flowering plants, 
3 younger ones, and 4o rosettes, and among the flowering indi- 
viduals 5 cana, 5 laeta, and 4 velutina. The cana were like those of 
the pure type; the Jaeta and velutina did not differ from those 
of the cross O. LamarckianaXO. Hookeri, some of the velutina being 
of a yellowish green in such a degree as not to be able to produce 
a stem. The reciprocal cross yielded only two Jaeta, one of which 
has flowered, among a culture of 60 specimens. The remainder 
were velutina, 24 flowering plants and 34 rosettes of radical leaves. 
The types were the same as those in the reciprocal cross. 
O. syrticolaXO. cana.—Represented by 60 specimens of the 
type of (O. syrticolaX Lamarckiana) laeta and velutina. Of these 
19 laeta and 6 velutina have flowered, reaching a height of 2 m. in 
