18 BULLETIN 1489, U. S. DEPARTMENT OF AGRICULTURE 
CHLOROPHYLL CHARACTERS 
There are several different seedling characters, some of which 
usually appear whenever self-fertilized corn is planted. Man} 7 of 
these are so deleterious that plants having them can not live beyond 
the seedling stage, while others are so weakening that affected plants 
rarely if ever mature under field conditions. Consequently they are 
carried only in the heterozygous condition and are not "prominent in 
fields grown from open-fertilized seed, though some may be found 
in practically every field of young corn. 
One of the most striking of these is the albino (white) seedling. 
As such an albino contains little or no chlorophyll, the green pig- 
ment by which the plant elaborates its starch, it can not live after 
the food supply from the seed is exhausted. One form of albino 
is due to the factor w, green plants carrying the dominant allelo- 
morph W and being either homozygous (W W) or heterozygous 
(W w). Selfed ears throwing these albinos produce about 3 greens 
to 1 albino, and whether or not any are produced from ordinary 
seed corn depends upon the chance union in the previous generation 
of a sperm and an egg both of which carried w (15, 5 4) • 
There also is a " virescent-white " type of seedling which resembles 
the albino at first but which soon begins to assume a yellowish green 
color and under favorable conditions may become entirely green and 
even mature its seeds. The factors concerned in this case are V v, 
virescent seedlings being v v and green seedlings V V or V v 
(16, 53). 
Seedlings carrying \ \ in addition to either w^w or v v are lemon 
yellow instead of white. Virescent yellow seedlings, l t \ v v, may 
become entirely green under favorable conditions and mature seeds 
as in the case of virescent white seedlings, L x L x v v. Yellow seedlings 
of the constitution \ l x w w, on the other hand, always die (5 If). 
Another type of yellow seedling which is distinctly deeper in color 
also has been reported. This behaves as a simple recessive to green, 
the factor pair determining its expression having been designated 
L 2 l 2 {55). 
The mode of inheritance for a large number of other abnormal 
chlorophyll types also has been determined. Some of these are 
apparent only in the seedling stage, others persist throughout the 
life of the plant, and still others appear only in the later stages of 
plant development. Japonica striping, the inheritance of which 
already has been considered, is an example of the latter condition, 
as the striping does not appear until the plants are six or more weeks 
old. Many other stripings are in this same class but need not be 
discussed in detail. So far as known they all are determined by one 
or more factors recessive to their respective allelomorphs for full 
green. 
A large number of different leaf spottings makes up a similar 
group. These are more difficult of classification, and their exact 
mode of inheritance has not been determined as completely as in the 
case of the stripings. There is every indication, however, that the 
genetic relations in this group are largely similar to those in the other, 
namely, that they are due to recessive factors, the dominant allelo- 
morphs of which are necessary for solid-green color- 
