468 BOTANICAL GAZETTE [DECEMBER 
calls chlorina, and the white-margined variety or albo-marginata are Mendelian 
in their hereditary behavior, both these forms being hypostatic to green and the 
chlorina hypostatic to albo-marginata. Two variegated varieties of Mirabilis 
Jalapa, on the other hand, give quite unexpected results. It appears that the 
offspring is more or less dependent upon the character of the particular branch 
upon which the seed was produced. Baur‘ has found a similar behavior in the 
white variegated Pelargonium; thus the offspring of a pure white branch gives 
nothing but pure white seedlings which are incapable of successful growth, while 
the offspring of pure green branches produce only pure green seedlings. PAUR 
goes into the anatomy of the white-margined varieties, and shows that there is a _ 
complete chlorophylless sheath overlying the chlorophyll-bearing tissues, and 
extending beyond them at the margin. Baur’s theory for the production of such 
variegated varieties is that the yellow and chlorophyll-bearing plastids are dis- 
tributed into the two daughter cells at each cell division, and by chance occasionally 
only nonchlorophyll-bearing plastids are included in one of the daughter cells. 
Thereafter this white cell gives rise to a cell progeny containing no chlorophyll 
and thus forming a white patch or streak which is the product of this one cell. 
When the division is anticlinal the variegation is in blotches, and when periclinal 
the white tissue becomes either median or marginal, only one case of the median 
type having been observed. Baur’s results seem to indicate that the male germ 
cells, as well as the female, contribute characteristic plastids to individuals pro- 
duced by their union, but this has not yet been actually observed. ‘ 
The possibility that different parts of a plant may present different hereditary 
qualities, as shown by Correns and Baur in these variegated varieties and as 
very generally recognized in the case of the relatively infrequent vegetative muta- 
tions known as bud-sports, is considered a matter of considerable importance by 
De Loacu,?? who seems to have found that in certain cotton hybrids some cap- 
sules of the heterozygote have the characters of the one or the other parent pract: 
cally “fixed,” while others give a large degree of splitting. Such suggestions 4S 
this open up interesting fields for investigation, but theoretically it does not 
seem likely that different parts of the same individual plant can generally have 
its own special type of heredity. 
EMERSON‘3 brings together the work that has been done in the study of 
Mendelian characters of beans, and finds that all evidence now at hand supports 
the reviewer’s statement that in certain varieties of beans a unit character for 
mottling is present, which produces an external manifestation only when in the 
tt Baur, E., Das Wesen und die Erblichkeitsverhiltnisse der “ Varietates albo- 
marginatae Hort.” von Pelargonium zonale. Zeitschr. Abstam. Vererb. 1:330-35" 
Jigs. 20. 1909. 
2 Dr Loacu, R. J. H., The Mendelian and DeVriesian laws applied to cotton 
breeding. Georgia Experiment Station, Bull. 83: 43-63. figs. 7: 1908. : 
3 Emerson, R. A., Factors for mottling in beans. Annual Report Ame ee 
Breeders’ Association 5: 368-376. 1909. 
