Morphologie etc. — Varietäten, Descendenz, Hybriden. 259 



erkennen lassen. Die Reduktionsteilung findet also gleich nach der 

 Befruchtung statt. Die dieser Teilung gewöhnlich folgende homöo- 

 typische Teilung, findet hier aber nur bei einem der Kerne statt, 

 bei dem Kern nämlich allein, aus dem die Kerne der Gonimo- 

 blastenzellen hervorgehen. Der Kern, bei dem diese homöotypische 

 Teilung unterbleibt, wird der Kern der Stielzelle. Wir haben da- 

 nach bei Nemalion den merkwürdigen Fall, dass bei der Reduk- 

 tionsteilung nur der eine Kern die homöotypische Teilung durch- 

 macht. In diesem Punkt verhält sich Nemalion anders als die von 

 Svedelius studierte nicht tetrasporenbildende Floridee Scinaia , 

 wo in regelmässiger Weise der heterotypischen Teilung die homöo- 

 typische beider Kerne folgt. Sierp. 



Saunders, E. R., The results of further breeding experi- 

 ments with Petunia. (Amer. Natur. L. p. 543—553. 1916.) 



The two main facts established by the earlier work were: 



1. That Singles of the cultivated forms of Petunia violacea, P. 

 nyctagiviiflora and of various garden strains (Countess of Ellesmere, 

 hybrida gvandiflora and others) give only Singles when self-fertilized 

 or crossed with pollen of other Singles. 



2. That these same Singles give a mixture of Singles and dou- 

 bles in F^ when crossed with the pollen of a double. 



In the present paper Miss Saunders publishes the results of 

 cross breeding experiments with new material, viz. w^ild plants of 

 Petunia nyctagini flava and of two new unnamed wild forms (species, 

 both white-flowered), all of which collected in Uruguay (by M. 

 Thays), and an entirely new stock of double material differing in 

 nature as well as in origin from that previously employed was also 

 now available. This was raised from seed of a plant, which had 

 some flowers double and others apparently of a normal Single struc- 

 ture (received from Hagedoorn) and from seed of an interesting 

 new strain (obtained by Mrs. Francis) of seed-producing doubles. 



The material employed has furnished no exception to the Sta- 

 tement that Singles crossed with the pollen of doubles yield some 

 doubles in F^ though breeding true to singleness when self-fertilized 

 or poUinated by other Singles. 



Very little evidence is yet available as to the results of using 

 the double plant as the seed-parent. Hagedoorn's plant was of an 

 exceptional character and the plants of Mrs. Francis, though more 

 typical, showed considerable sterility, but seem to breed true in 

 doubleness. M. J. Sirks (Bunnik). 



Surface, F. M., A note on the inheritance of eye pattern 

 in beans and its relation to type of vine. (Amer. Natur. 

 L. p. 577- 586. 1916.) 



A cross between a bean with typical Old-Fashioned Yellow Eye 

 color pattern O.F.Y.E. and a bean of typical Improved Yellow Eye 

 color pattern (I.Y.E.), gave as F^ (in total 295 beans) only plants of 

 the so-called „piebald" color pattern, in which the colour pattern 

 is much more extended than it is the case in one of the parents. 

 The F2 cultivated gave 146 piebald: 53 I.Y.E. : 70 O.F.Y.E., the 

 theoretical ratio being 8:3:4. This theoretical ratio seems to con- 

 clude very nicely with the data at band, and is explained by the 

 writer in this manner: Let I be the factor which in its homozvgous 



