Varietäten, Descendenz, Hybriden. 567 



2) Families horaozygous for L or 1: the reduplication be- 

 tween ß X E is 127 : 1 or 1 : 127 according to whether matings are 

 of the form BE X t>e or Be X bE. 



3) Families homozygous for B or b: data are not fully avail- 



able yet. 



4) Families heterozygous in all three factors: In matings 

 of the form BEL X bei reduplication between B X L is now no 

 longer on a basis of 7 : 1 but more nearly 5:1; also between B X E 

 is now more nearly 63: 1. It is concluded therefore: that what may 

 be termcd the normal linkage ratios are affected by the heterozy- 

 gous nature of the third factor. The same kind of phenomena were 

 met with in another series of families in which the characters 

 involved were "dark axil", "fertile anthers" and "normal fiower" as 

 opposed to "light axil", "sterile anthers" and "cretin flower". 



Simple 9:3:3:1 ratios also appeared in some crosses. The 

 author points out that results calculated on Trow's hypothesis of 

 primary and secondary reduplicated series agree closely with expe- 

 riraental numbers. 



Diagrams are appended suggesting that the form of the series- 

 whether even or odd-may possibly depend on whether the first 

 division in the quadrants is periclinal or anticlinal. 



W. Neilson Jones. 



Saunders, C. R., Further contributions to the study of 

 inheritance of hoariness in Stocks (Matthiola). (Proc. Royal 

 Soc. 85 B. NO. 582. p. 540—545. 1913.) 



The author's conclusions may be summarised as follows: 



1) Sap colour in Stocks is due to the presence of two factors 

 (C-t-R): in the absence of either or both the sap is colourless. 



2) Hoariness depends on the presence of two factors (H -|- K) — 

 the plant being glabrous in the absence of either or both. 



3) The hoary effect of H -j- K is manifested only when C -f R 

 are both present in addition (i. e. hoary plants contain all four factors). 



The toUowing generalisations may be made with regard to be- 

 haviour on breeding. 



4) Glabrous plants bred together may yield an F^ («) all hoary 

 (b) mixed hoary and glabrous or {c) all glabrous. 



5) When F^ from unions between glabrous plants is all gla- 

 brous all later generations from F^ will be glabrous. 



6) When F^ from such matings is all hoary, F2 will contain , 

 hoary and glabrous in proportions depending on whether F^ is 

 heterozygous in 2, 3, or 4 factors. 



Thus : F, heterozygous in 2 factors will give a ratio 9 hoary : 7 glabrous 



^ 97 37 



,1 ,) H '-' 1) )1 " V )) ^' )) ^' " 



„ ,1 )) '^ 11 11 11 )> 1» ^t „ 1/D „ 



7) When hoary and glabrous plants are crossed there may be 

 in addition the above: the ratio 3 hoary: 1 glabrous where F^ is 

 heterozygous for only one factor. 



In the earlier accounts the author postulated two factors H -f- K 

 for hoariness. Since types HK -}- Hk only were met with, one of 

 these factors was subsequently omitted. Recently however the author 

 has used another type of glabrous plant which from its behaviour 

 proves to be of the form hK. The earlier hypothesis is thus proved 

 correct and is now adopted. W. Neilson Jones. 



