1916] _ DEVRIES—DIMORPHIC MUTANTS 255 
marckiana mut. nanella and none of those of O. cana. This has 
been the case in some of the other pedigree cultures of this type, 
but it should be remarked that in other cases the characters of 
O. cana may combine with the dwarf stature. Such dwarfs have 
the narrow gray foliage and are easily distinguished from typical 
O. nanella specimens. 
The self-fertilized seeds of the cana individuals split in both 
generations into cana and Lamarckiana, just as O. scintillans splits 
into scintillans and Lamarckiana. The proportions 16-24-34 
per cent with a mean of 25 per cent seem to indicate a splitting 
into nearly equal parts, with a loss on the side of the weaker form. 
The same déviation from equality will be seen in almost all the fig- 
ures of this article, and the same explanation must be considered 
as applying to allofthem. It is almost always the new type which 
is in the minority.® 
The seeds of the Lamarckiana-like individuals do not give rise 
to a splitting of this kind, keeping true to their parent form. The 
same fact recurs in all the pedigrees to be mentioned later on, and 
for all the new dimorphic types. It may be taken to be the rule, 
therefore, although the trials have been only one or two in each 
instance. It agrees fully with the behavior of the analogous split- 
ting products of O. scintillans. 
O. cana from lata nos. 2 and 3.—In a culture of about 600 
seedlings of O. lata, 4 mutants of the cana type arose in 1908. 
The /ata strains had been derived from some annual mutants which 
had been produced by my O. Lamarckiana in 1905, and described 
in my Gruppenweise Artbildung (p. 247). From these mutants 
a second generation was cultivated in 1907, and fertilized by the 
pollen of Lamarckiana-like individuals of the same culture. Their 
seeds yielded the two cana mutants to be described here, and two 
others, from the seed of which only one generation has been studied. 
The pedigree of mutant no. 2 is given below: 
1908... :; Mutant Mutant 
Tors) Second generation 35 Peas tems 
Le, cain Third generation 15 percent cana ~~Lamarckiana = Lamarckiana 
* Excepting the case of biennials; see later statement. 
