1914] CURRENT LITERATURE 79 
between them and the parents or the smallest of other F, forms is not bridged, 
and there are no compensating giant forms. It seems more likely that these 
plants are dwarfs because of some abnormality of function, and that, so far as 
to a recombination of other genetic factors present in the parents. The fact 
that the dwarfs have occurred in some cultures in ratios much above 1:15 need 
occasion little worry at the present stage of the investigations, since students 
of- genetics are coming to look to ratios merely for indications, and to base 
conclusions rather upon a factorial analysis of the material, worked out by 
intercrosses of the diverse types of the culture concerned or by back crosses 
with the parents. 
Davis’ results as a whole are of the greatest importance. It is hoped that 
he will find the time in the near future to subject his material to statistical and 
factorial analysis in the same painstaking way that has given-the brilliant results 
secured in his attempted synthesis of Oenothera Lamarckiana. 
HERIBERT-Nitssons has reported the results of a study of Oenothera 
Lamarckiana and its derivatives. His cultures exhibited numerous heritable 
differences with regard to such characters as color of leaf veins and leaf blades, 
breadth of flowers, length of fruits, and height of plants. The appearance of 
these minor forms in cultures of Lamarckiana is regarded as an indication that 
the species is not a constant one. The characteristics by which these forms are 
istinguished are the same, in part at least, as those that serve to differentiate 
the mutations of Lamarckiana. This fact suggests to the author that the muta- 
tions are the result of new combinations of characters, or factors, present in the 
parent species. 
€ mutations that appeared in HERIBERT-NILSSON’s cultures were not 
identical with those of De Vries. Some of them were entirely unlike DE 
Vries’ mutations, while others were parallel types. Some of the latter 
resembled rubrinervis, gigas, albida, and Jata, for instance, in certain respects, 
but differed from them in others. Certain of the author’s mutants combined 
important characteristics of several of Dr VRIES’ mutants. One, for instance, 
exhibited characters of rubrinervis, scintillans, and lata. The forms studied 
differed principally in quantitative characters, a fact that makes a factorial 
analysis a matter of extreme difficulty. The behavior of certain qualitative 
characters, particularly red color of leaf veins, indicated that two or three Men- 
delian factors ts might be concerned. Ratios of red-veined to white-veined indi- 
viduals occurring in the F; generation of a giant form approached 3:1, 15:1, 
and 63:1. A complete factorial analysis of these groups, based upon a study 
of their Progenies, has apparently not as yet been attempted. HERIBERT- 
NItsson’s suggestion that giant (gigas-like) oenotheras have arisen through 
‘Hertwert-Nitsson, H., Die Variabilitit der Oenothera Lamarckiana und das 
Problem der mutation. Petes, Ind. Abst. Vererbungs. 8:89-231. 1912. 
