6. Vererbungslehre. 839 



t'nuii F, plants Belfed gave 111 thick and long (tall), :;."> thick and short 

 (half-dwarf), 82 thin and long (half-dwarf ) , 13 thin and Bhort (dwarf); thus 

 oearly in the ratio of 9 : 8 : 8 : 1. The fall character La therefore probably 

 due to the eoexistence of thickness of stein with long internodes; the absence 

 of either one of these factors produces half-dwarf; of both, fully dwarf peas. 

 Experiments on earliness or lateness of Bowering showed that while there are 

 indications that lateness is dominant to earliness, yet plants with long inter- 

 oodes flower on the whole earlier than those with -hört, and there is also an 

 indication that there may be coupling between thickness of atem and lateness 

 of flowering. The physiological causes involved require further investigation, 

 and in order to show whether earliness and lateness of flowering are an 

 allelomorphic pair, varieties which differ in this character only must be used. 



Doncaster (Cambridge). 



1809) Keeble, F. and C. Pellew (üniversity College, Reading) , White 

 flowered varieties of Primula sinensis. 



(Journ. of Genetics 1,1. p. 1 — 5. 1910.) 

 In Primula sinensis the wdiite colour of wdiite flowered varieties with 

 red stems is generally dominant when crossed with coloured- flowered forms, 

 but the white of rlowers having green stems is recessive to colour. The au- 

 thors show that in the variety "Snow King' (white rlowers and dark red stems) 

 plants of various gametic Constitution occur, allthough the variety breeds trne 

 when Belfed, On crossing with coloured varieties in different cases the F l 

 offspring were (1) all white, (2) half white (tinged) and half - coloured, or 

 (3) all coloured. The coloured F, plants selfed gave coloured to white in 

 the ratio of 3:1; the tinged wdiite F } plants in the ratio of 3 : 13. This 

 indicates that some plants of 'Snow King' lack a colour factor in the flower, 

 though the stem is red; others are homozygous for a dominant white factor; 

 and others again lack a colour factor and are heterzygous for dominant white. 

 By crossing 'Snow King' with the wdiite green-stemmed 'Snowdrift' an F, ge- 

 neration of uniformly coloured flowers was obtained. 



Doncaster (Cambridge). 



1810) Doncaster, L. and F. H. A. Marshall (üniversity of Cambridge). 



The Effects of one-sided ovariotomy on the sex of the offspring. 

 (Journ. of Genetics 1,1. p. 70—72. 1010.) 

 In order to prove whether ova prodnced by one ovary give rise to young 

 of one sex, and those from the other ovary to the other sex, as has been 

 Buggested, the right ovary was removed from one rat, the left from another. 

 Alter recovery l»oth rats became pregnant and bore young. The first rat pro- 

 duced 4 females, 1 male, and two in which the sex was not determined; the 

 second rat produced 3 females and 2 male-. The parents were then killed 

 and examined and qo trace of ovarian tissue conld be found on the side from 

 which the ovaries had been removed. In the rat from which the right ovary 

 was removed the left ovary contained at least 7 Corpora lutea; the right 

 ovary of the other contained 8. It is therefore concluded that in the rat the 

 sex of the young is not determined by the ovary from which they are derived. 



Donca ster (Cambridge). 



1811) Saunders, E. R. (Newnham Collen-, Cambridge. Studie- in the 

 Inheritance of Doubleness in Flowers. I. Petunia. 



(Journ. of Genetics l.i. p. 57—69. 1 plate. 1910.) 



Single Petunias of various races, even when they have a double parent, 

 when selfed or crossed together, give only Singles. 



Zentralblatt f. allg. u. exp. Biologie. I. 55 



