374 Referate. 
A most interesting relation between color hypostasis and albinism is 
pointed out. It is shown that whenever two pigmented races are crossed, 
which have no color modifier in common, albinism must appear in a certain 
proportion of the offspring, the proportion depending on the number of 
color-factors present. Thus if B, D and R be each capable of producing 
pigmentation, the cross between two pigmented beans, BBddRR and bbDDrr, 
will produce one albino, bbddrr, in sixty-four F, offspring, tho neither of 
the parent-strains has ever been previously crossed with white. If the 
parents differed in regard to four color-factors, none of which were possessed 
in common, there would be one white in 256 individuals, and so on. 
Crossing a white bean produced in this manner with another white bean 
which lacks chromogen but possesses a pigment-modifier, would result in 
a progeny of pigmented beans, in the same manner that crossing two 
white sweet peas produces colored offspring, but no such result has yet 
been gained by crossing beans. 
It is also shown that the 3 to I ratio should be expected in the Fa 
of a cross between pigmented and white beans only (a) in case the white 
bean lacks pigment and has at least one modifier in common with the 
pigmented bean with which it is crossed, or (b) in case the white parent 
has chromogen but lacks all pigment-modifiers and the pigmented bean 
with which it is crossed has only one pigment-modifier. In any other case 
the ratios will range from 2.4: 1 to nearly 3:1, depending on the total 
number of pigment-modifiers involved. This may account for an excess 
of white beans beyond the 25 per cent expected in certain crosses. 
Geo. H. Shull. 
Hase, Albrecht. Über die deutschen Süßwasserpolypen Hydra fusca L., Hydra 
grisea L. und Hydra viridis L. Eine biologische Vorarbeit, zugleich ein 
Beitrag zur Vererbungslehre. Arch. f. Rassen- u. Gesellschafts-Biologie. 
6. Jahrg. 6. Heft. 1909. S. 721753. 
Untersuchungen über das Lebensalter der Süßwasserpolypen ergaben, 
daß /. grisea mit einer durchschnittlichen Lebensdauer von 95 Tagen älter 
wird als 77. fusca mit rund 35 Tagen. Dementsprechend kommt der ersteren 
ein kleinerer Vermehrungsfaktor für den Tag zu. Allerdings schwankt bei 
jeder Art die Fruchtbarkeit individuell. 
Die Tentakelzahlen erwiesen sich als reine nicht erbliche Somationen, 
die mit dem Alter zunehmen; während die im höheren Alter abgeschnürten 
Knospen nicht die Tentakelzahl der Mutter besitzen, sondern eine geringere, 
der Grundzahl der Spezies angenäherte. 
Hanelhat also mit Unrecht ihre nach der Tentakelzahl charakterisierten 
Linien mit den reinen Linien Johannsens gleichgestellt, denn bei den 
letzteren handelt es sich um ein für Eltern und Nachkommen konstantes 
Merkmal. Hilzheimer-Stuttgart. 
East, E. M. The transmission of variations in the Potato in asexual repro- 
duction. Connecticut Agr. Expt. Station Report. 1910. S. 119—160. 
plates 5. 
This paper shows the similarity between the inheritance of fluctuations 
in asexual reproduction in multicellular organisms, and that in the pure lines 
of Johannsen and Jennings. It is found that neither the relative content 
of dry matter nor that of the nitrogenous matters of the tuber can be 
