622 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



" homozygous " condition. When a character is found in only half 

 the reproductive cells, it is said to be in a " heterozygous " condition, 

 and progeny of different types are produced. 



A certain stimulus to development probably accompanies every act 

 of fertilization, but what is of special interest to corn-breeders is that 

 this stimulus is far greater in a hybrid than in a pure-bred variety, since 

 these so-called pure-bred varieties are in fact only varieties exhibiting 

 characteristics perpetuated by man through selection, such selection 

 being obviously only another name for in-breeding. It so happens that 

 isolation is not in practice a very easy matter with Indian corn, since the 

 plant is naturally constructed for cross-fertilization, and the pollen, 

 being produced in enormous quantities, is widely carried by the wind; 

 and since an immediate cross between two types is more vigorous and 

 productive than either type in a pure state, it follows that when the best' 

 ears are chosen in a field for perpetuation, just those are likely to be 

 selected which are in a hybrid condition and which will not breed true. 



Tables are here given showing the effect of in-breeding on yield and 

 giving the comparative yield of normal corn, in-bred corn, and of various 

 crosses, all which make it clear that the increase of vigour due to cross- 

 ing is obtained only in the first hybrid generation. It appears therefore' 

 that, to obtain a crop of corn showing uniformly desirable characteristics! 

 and at the same time vigour of growth, it is necessary to in-breed tw^oj 

 strains until those characteristics have become fixed, and then cross to| 

 obtain vigour of constitution, and to repeat this process for every com- 

 mercial crop. As this would be obviously an unprofitable proceeding! 

 financially, this bulletin suggests further experiments with first crossesl 

 between several of the well-established strains of corn already grown| 

 in different parts of Connecticut. — M. L. H. 



Cotton, Hindi, in E^ynt. By 0. F. Cook (U.S.A. Dep. Agr 

 Bur. PI. Ind., Bull. 210, May 1911; plates).— So far all attemptsj 

 at acclimatizing the higjh-priced Ee^yptian varieties of Cotton in 

 America have been prejudiced by the difficulty in keeping the crop pure 

 Partly this is due to the fact that it is grown in the same localities as! 

 American Upland Cotton and is hybridized with that by bees, but the| 

 imported Egyptian seed itself is contaminated with what is known as 

 " Hindi " Cotton, an inferior plant, which is nearly always to be founcj 

 in Egyptian Cotton-fields. Its presence is not so serious a matter there|( 

 as labour is so cheap and plentiful that it pays the grower to have thf! 

 Cotton sorted by hand after gathering. In America, however, lab od 

 conditions are so different that this would not be profitable, and thii 

 Bulletin suggests other ways of coping with the evil. 



The injury caused by Hindi contamination is not limited to th^ < 

 proportion of Hindi plants and obvious hybrids that are counted in th | 

 fields. Many plants not readily distinguished as Hindi hybrids a ^i 

 earlier stages of growth give later indications of hybrid nature in whitj k\ 

 flowers, pale-green bolls, sparse, inferior lint, or in relative or completj |i| 

 sterility. 



