452 Varietäten, Descendenz, Hybriden. 



Immunity is independent of anj- discernible morphological cha- 

 racter, and it is possible to breed varieties morphologically similar 

 to one another, but immune or susceptible to the attacks of certain 

 parasitic fungi. R. C. Lock. 



Biffen, R. H., The Hybridisation of Barleys. (Journal of agric. 

 Science II. p. 183—206. 1907.) 



The author refers to Rimpau's work on the crossing of barleys, 

 and points out that that writer must have come very near to making 

 an independent discovery of Mendel's laws of inheritance. 



The Classification oi Hordeuni sativuni used is that of Kornicke 

 as modified by Beaven, the following subspecies being recognised : 

 H. hexastichum (six rowed); H. vulgare (also six rowed); H. intertne- 

 diuni (with small awnless lateral florets which set grain as a rule); 

 H. distichmn (with a median fertile floret and laterals staminate 

 only); H. seocriton (as the last with a dense ear); H. decipiens (\ater als 

 still further reduced). A number of varieties of each of these sub- 

 species is described. 



An account is given of the characters dealt with and of the 

 method of pollination. The following are some of the most important 

 results recorded. 



Sexless and staminate lateral florets: In Fl the sexless character 

 is dominant; in F2 plants with staminate, with small staminate and 

 with sexless lateral florets appeared in the ratio of 1:2:1. 



Hermaphrodite and sexless lateral: The heterozygote showed 

 truely staminate laterals, in F2 füll}'- fertile, staminate and rudimen- 

 tary lateral bearing tj^pes were found in the proportion 1:2:1. 



Staminate and hermaphrodite lateral florets: The first generation 

 with some doubtful exceptions was intermediate; in F2 six row, 

 intermediate and two row forms exhibited the ratio 1:2:1. 



"Hooded" or Trifurcate and Awned paleae: The hooded form is 

 dominant. 



The purple and black colours in the paleae are dominant to 

 the absence of these colours respectively, and narrow glumes are 

 dominant over broad glumes. 



Lax and dense ears: Fl was shown by measurement to be 

 slightly denser than the lax parent. The F2 generation consisted in 

 each of three cases of plants with ears as lax or as dense as those 

 of the parents, together with a series lying between these extremes. 

 Measurements and the growth of a further generation showed that 

 there is a group of pure extracted dense forms which show however 

 some variability among themselves in the degree of denseness. 



Adhercnt and Non-adherent paleae: "Taking the evidence as a 

 whole it appears that the trapped (adherent) condition comes verj" 

 close to being dominant over^the naked, but in view of the difficulty 

 of separating the forms in the F2 it is best treated, for the present, 

 as giving an intermediate with partially naked grain. 



Brittle and Tough Rachis: the former is dominant. 



R. H. Lock. 



Pernald, M. L., Streptoptis oreopolus a possible hybrid. (Rhodora. 

 IX. p. 106 — 107. June 1907.) 



S. oreopolus is recorded as sterile, while the associated S.roseus 

 and 5. amplexijolius were fertile. Trelease. 



