1916] DEV RIES—DIMORPHIC MUTANTS 265 
PEDIGREE OF MUT. pallescens NO. 3 
Toit. .Mutant Mutant 
1913. .Second generation 36 per cent pallescens Lamarckiana 1 mut. cana 
1914. .Third generation 39 per cent pallescens Lamarckiana Lamarckiana 
The size of these cultures is given in table VI. 
TABLE VI 
wee Generation Parent odenting individuals B ene mmc Mutants 
A 
Rs) Ge Game: TUG HGS Eh ON ee Ee pad ee Poe es oie gee 
$933 52). Second mutant 25 25 28 1 rubrinervis 
$6ta. Third pallescens 57 57 42 | 5 nanella 
19t4). . 2. Third Lamarck- 60 25 Sen ee Ue manasa 
ian: 
B 
SOUT yy PAOTANE HOSS Oe ae es Le ee Sena we cee We eb 
vote. cS. cond mutant 25 25 36 I cana 
Soka... pallescens 25 25 39 r lata, 3 na- 
nella, 1 cana 
pnb 7 Benner Third Lamarck- 65 25 COG oe oleae oo ne om 
Among the mutants the rubrinervis, both cana, one lata, and 
some nanella have flowered. The individuals of pallescens and 
Lamarckiana, which did not flower, were examined in June 
and July as large rosettes. Most of the flowering specimens were 
observed during the months of August and September. 
The percentage figures of these tables vary from 23 to 43, the 
means for the 3 families being 33, 35, and 37 per cent, and the total 
mean being 35 per cent. On account of the evident weakness of 
the individuals of the pallescens type, as compared with their 
Lamarckiana-like sisters, these figures may be assumed to show 
that the splitting into two main types took place in about equal 
parts. The splitting is constantly repeated from the fallescens 
Specimens, but the progeny of the Lamarckiana type retain this 
type uniformly. 
I have made only one cross in these families, and that in order 
to ascertain the properties of the pollen of the pallescens indi- 
viduals. I placed this pollen on the stigma of some flowers of 
