NOTES AND ABSTRACTS. 



of ammonia producing country, but in recent years Germany has 

 taken the first place. 



Of the amount produced in 1912 in the United Kingdom, 287,000 

 tons were exported, so that the balance remaining for home consump- 

 tion was approximately 90,000 tons. The exports of sulphate of 

 ammonia are principally to the United States, Japan, Spain, Dutch 

 East Indies, and Italy. — A. S. 



Sulphur as a Dressing for Turnips and Beets. By M. A. 



Magnieu {Jour. Soc. Nat. Hort. Fr. Jan. 1913, pp. 54, 55). — M. 

 Magnieu reports favourable results from two experiments in the use 

 of sulphur as a dressing, one for turnips and one for beetroot. In 

 the former case the sulphur was sown broadcast at the rate of 2 grammes 

 of flour of sulphur to the square metre. In the latter experiment the 

 sulphur was not weighed, but it may be put down as about 2 or 3 

 grammes to the metre along the drills. — M. L. H. 



Sweet Potato, The Black-rot and Stem-rot of the. By L. L. 



Harter {U.S.A. Dep. Agr., Bur. PI. Ind., Circ. 114; Feb. 1913 ; 

 pp. 15-18). — ^This paper outlines what are believed to be the most 

 effective means of controlling these diseases, though some of the 

 recommendations are tentative only and may require modification 

 upon the completion of experiments which are now in progress. — A. P. 



Thiaspi, Pollination of. By Rob. Stager {Beih. Bot. Cent. 

 XXX. Ahi. I, Heft i, pp. 17-23). — ^The flowers of Thiaspi rotundijolium 

 have been described as capable or as incapable of self-poUination 

 and as both dichogamous and monogamous. All these various 

 methods occur according to conditions of weather and of altitude. 

 In the Tyrol, anthers and stigma ripen together, but there is no self- 

 poUination. At 500 metres and 2200 metres (Ziirich and Jorat) the 

 flowers are protogynous and not self-poUinated ; but at Susanpe 

 (2200 m.) self-pollination occurs at close of flowering. At very high 

 altitudes, 2600 metres and over, the flowers remain protogynous, 

 but self-pollination is more distinct ; yet even at Rohrbachstein 

 (2900 m.) cross-pollination occurs. 



The growth of the style and turning back of the stamens prevent 

 self-pollination even at 2200 m. in sunny situations ; but this does 

 not happen at higher altitudes, even on very warm days, for the nights 

 are very cold. — G. F. S. E. 



Thorn, a twice-flowering Variety. By G. Gibault {Rev. Hort. 

 p. 26, Jan. 16, 1914). — A description of a tree which, on the Hnes of 

 the Glastonbury Thorn and a similar example described by Prof. C. 

 Avelon in the previous number, flowered persistently at Christmas, 

 as well as at the normal time, all three being traditionally imputed to 

 saintly influence. None of these apparently could be propagated so 

 as to reproduce their peculiarity. — C. T. D. 



