84 GENETICS [Bot. Absts., Vol. IV, 



pelliculatus have a white cell layer below the epidermis and a green core, thus showing green and 

 white in the leaves. Chlorotidermis has a bright yellow-green subepidermal layer and a green 

 core. — Leucodermis and albopellicxdatus are classed together since both transmit the white "dis- 

 eased" condition of the subepidermal layer to their seedling progeny. This transmission is 

 produced only through the egg cells, not through the pollen. The genotype of the nucleus 

 is the same in both the white subepidermal layer and the green core. — Pseudoleucodermis 

 and chlorotidermis are similar. In this case, the seedling progeny inherits the white or pale 

 green character of the subepidermis through a definite Mendelian factor that is recessive to 

 normal green. There is no transmission or cytoplasmic inheritance here. The nucleus of 

 the white or pale green subepidermis contains this recessive factor, while the green cells 

 of the same plant contain the dominant allelomorph in a homozygous or heterozygous 

 condition. — E. W. Lindstrom. 



551. Correns, C. Vererbungsversuche mit buntblattrigen Sippen. I. Capsella bursa- 

 pastoris albovariabilis und chlorina. [Genetical studies with variegated races. I. Capsella 

 bursa-pastoris albovariabilis and chlorina.] Sitzungsber. K. Akad. Wiss. Wien 34: 585-610. 

 1919. — The chlorina race of Capsella is a pale-green type which is inherited as a simple Mende- 

 lian recessive to normal green. A physiological examination of the chlorophyll content indi- 

 cates that there are two kinds of chlorina plants, one euchlorina with 45 per cent and the other 

 subchlorina with 65 per cent of the normal chlorophyll content. — The albovariabilis race is a 

 white-variegated type that shows a great deal of variation in the proportion of green and 

 white areas in the leaves and seed capsules. The author says that the albovariabilis character 

 may be thought of as a disease, the inheritance of which is governed by a Mendelian pair of 

 factors. Albovariabilis is recessive to normal green. In the Fo generation both 3:1 and 15:1 

 ratios were obtained, indicating that there are two pairs of factors concerned. — Selection for 

 increase of green or of white variegated progeny from albovariabilis was effective. This, the 

 author is inclined to attribute to the action of modifying genes. The selection process had two 

 general effects, one a temporary and the other a permanent one. 



The temporary result which last only as long as selection continued, was obtained when 

 the selection was in the direction towards increased amount of variegation. The permanent 

 result was achieved when the selection was made towards full green. — E. W. Lindstrom. 



552. Costantin, J. La mutation. Etat actuel de la question. [Mutation. Present status 

 of the question.] Ann. Sci. Nat. Bot. X. 1: iii-xxix. 1919. — Of various mutants reported 

 by De Vries author dwells particularly on Oe. gigas; at first anomalous in that it originated 

 only once in early culture. More recently Gates studied a gigas that originated at Palermo 

 and Heribert-Nilsson obtained a gigas mutant at Lund. Gates linked up gigas traits with 

 doubling of chromosome number which led to enlargement of individual cells. Author cites 

 work of the Marchals who by cuttings from sporophytes of mosses secured 2x gametophytes 

 different from lx gametophytes; considered mutation experimentally produced; refers to rela- 

 tion of cell characters to chromosome number in the Marchals' moss mutations, Oenotheras, 

 and in banana varieties. After emphasizing cases connected with alteration of chromosome 

 numbers author refers briefly to Bab cock's discussion (1918) on factor mutation in plants with 

 same visible chromosome complex. Author considers possibility of the Oenothera mutation 

 phenomena being results of a previous hybridization as suggested by Bateson and Saunders 

 in 1902, opposed by MacDougal (1903), reaffirmed by Davis (1911), who synthesized a La- 

 marckiana-like form, and by Lotsy (1916), who considered 0. Lamarckiana a heterozygote 

 on basis of crossing results. Leclerc de Sablon explains Oenothera mutation phenomena on 

 basis of heterozygous factors that are linked and thus show reduplication at gametogenesis. 

 The nanella mutant is discussed and Zeylstra's discovery of bacterial parasite often associated 

 with nanism. Two mutations in Capsella are considered by author large enough to be 

 generic changes, i.e., C. Hecgcri, whose capsule resembles that in genus Camelina and C. 

 Viguicri with capsule like that of genus Holargidium. Theoretic edifice of De Vries (pan- 

 genes in active, inactive, and labile conditions) is given to explain mutation and remarkable 

 hybridization results in Oenotheras. Origin of labile (unstable) pangenes from others gives 



