1764 PJ,ANT-BREEDING 



generation. If all the ovules were fertilized by heterozygous pollen 25 per 

 cent of white individuals could be produced. As this probability is excluded 

 this 25 per cent represents the maximum theoretical limit of probability, and 

 the actual number of white descendants appearing in the Fg generation of 

 a single crossing is determined only by the frequency with which plants 

 predisposed to lack of chlorophyll occur in the neighbourhood. This explains 

 why the number of white plants appearing in a single line or rye is relatively 

 so small, although such plants occur in a large number of lines. 



It is evident that tlie appearance of white plants is of extraordinary 

 frequency in the rye under discussion. On the other hand such plants were 

 rarel} seen in 30 other kinds of rye grown at the Experimental Station. Saa- 

 leroggen is a local variety peculiar to the environs of Halle and it hs been 

 grown for a long time without the introduction of fresh blood. As it has 

 been grown by in-breeding there is every reason to believe that this method 

 of cultivation is the cause of the lack of chlorophyll. This hypothesis is 

 rendered more probable by the fact that the appearance of white plants seems 

 to increase steadily in spite of the dominance of the factor " presence of chlo- 

 rophyll ". 



As in the observations made b}^ Nilsson-Ehle, the heterozygous plants 

 of barley and rye which are the parents or even the sister-plants of the albinos 

 in the Halle district are in no way different from the normal homozygous 

 plants of the varietj'. The green chlorophyll is strongly dominant, but this 

 dominance seems only to occur in indigenous cereals, as Emerson has found 

 in Maize some heterozygous plants of an intermediate type striped with green 

 and white. 



1273 - Two New Seedling Hops of Commercial Promise. — vSalmon e. s., in journal of 



the Board of Agriculture, Vol. XXIII, No. I, pp. 47-51. I,ondon, April 1916. 



In 1906 the writer commenced to raise new varieties of hops from seed 

 obtained by artificial and by natural cross-fertilisation, and at the present 

 time the Iviperimental Hop-garden at Wye College contains nearly 4000 

 " hills " of seeding female hops and selected male hops. The commercial 

 value of the most promising of the seedlings is now being tested. 



In a preceding article {Journal of the Board of Agriculture, May 1915) 

 attention Vv^as drawn to a new hop, the P'oundling, which is resistant to the 

 eel worm disease and shows other characters of commercial importance; in 

 the present paper two other seedlings are described which appear worthy 

 of more extended trial by the hop-growers of this country. 



The first of these new varieties was raised in 1906 by pollinating the 

 variety White's Early with Early Bird. All the plants thus obtained showed 

 a lesemblance to White's P'arly in earliness, in the large, 1)old, rather open 

 hops with thin petals, and in possessing the delicate " Golding " flavour. 

 Two or three of the seedlings show promise commercially, but only one 

 (No, 125), called Young Hopeful, has yet been tested sufficiently. The dry 

 hops for .-everal seasons have been favourabh' reported on by various experts. 

 In iqio and 1911 the ho])s contained 8.66 per cent of soft resins ; in 1912 the 

 percentage was 10.30. During the last three years cuts of this plant have 



