NOTES AND ABSTRACTS. 



645 



Guatemala Plants. By John Donnell Smith {Bot. Gaz. vol. Hv. 

 pp. 235-244; Sept. 1912). — New species of Rigiostachys, Eugenia, 

 Anquria (2 spp.), Gurania, Alloplectus (3 spp., with key to others), 

 Besleria, Phyllanthus, Hieronyma, Croton (2 spp.), Acalypha, Con- 

 ceveiha, and Ampelocera. — G. F. S. E. 



Hawaii Annual Report Agrr. Exp. Stn. for 1910. By E. V. 



Wilcox (May 1911 ; illustrated). — It being impossible to construct and 

 carry on demonstration farms on each island, a plan has been adopted, 

 which works well, of selecting the holding of the most progressive 

 farmer in each locality and, with his co-operation, carrying out the 

 improved methods of cultivation that it is thought desirable to introduce, 

 with careful checking of results in each case. 



The soil in Hawaii, being highly manganiferous and ferrous, requires 

 mechanical improvement rather than actual fertilizing. 



In the case of pineapples, the phosphatic manures seem to be 

 beneficial, as tending to render the manganiferous salts less soluble, 

 but lime, on the contrary, combines with the latter and forms the 

 injurious higher oxide of the mineral. The sugar-content of pineapple 

 is proved to be supplied entirely from the leaves, and when cut green, 

 it remains stationary, " ripening " merely softening the tissues of the 

 fruit, and not increasing its sweetness. They should therefore be cut 

 only when the fruits have turned yellow about a quarter of their 

 length. 



Eice benefits from manuring in its quite early stages, and nitrogen 

 has more value for it than potash and phosphates. If given in the 

 form of sulphate of ammonia, nitrogen has a marked beneficial effect, 

 whereas nitrate of soda appears to have none. 



The chief cottons grown are Oaravonica and Sea Island, the former 

 being preferable on account of its upright habit of growth, whereas the 

 very productiveness of the latter is a disadvantage, as the weaker stems 

 cannot support the weight of the bolls, which are apt to rot from 

 lying on the ground. 



With rubber, clean cultivation would seem to be far more important 

 than fertilizers. Trees which had received clean cultivation since 

 planting were larger at two years of age than six-year-old trees under 

 no cultivation. 



Arsenite of soda as a spray was used to keep down weeds where it 

 was too rocky to cultivate. 



The Ceara rubber grows more rapidly in Hawaii than Hevea, and 

 will probably be more extensively planted. — C. H. L. 



Hawthorn Seeds, After-Ripening of. By Wilmer E. Davis 

 and E. Catlin Eose {Bot. Gaz. vol. liv. pp. 49-62; July 1912).— The 

 authors point out that freezing, and sometimes freezing and thawing, 

 accelerate the ripening of various seeds. Crataegus mollis seeds do 

 not usually germinate till two, or even three, years after maturity. 

 The authors found no germination for months, even after carpellary 



