Agricultur. — Horticuitur. — Forstbotanik. 



351 



the starch in the cultivated potato by quite 40 per cent., in addition to 

 creating races of higher agricultural yield and vigour. 



As is the case among many other economic plants several factors 

 have to be regarded in seiection experiments and in the potato in addi- 

 tion to starch content, the character of the skin, „eyes", fibre and in parti- 

 cular the structure of the starch granuies are of the highest importance 

 from the point of view of the starch manufacturer. 



Below are given the results of 38 analyses of Germ an potatoes 

 by Morgen, and of 21 analyses of Jamaican cassavas by Cousins: 



Cassava in Jamaica has a great advantage over the potato in 

 temperate climates, owing to its immunity to disease^ and its unrestricted 

 season of growth and harvest. 



The process of preparation of potato starch is described, and an 

 estimate given of the cost of a factory. Of potatoes containing 24 per 

 cent. of starch 4,4 tons are requried to pcoduce a ton of commercial 

 starch. 



The advantage of cassava in Jamaica over the potato in Ger- 

 many^ apart from the intrinsic superiority of cassava starch, qua starch, 

 is 2 to l, ton for ton. 



It is estimated that an efficient starch factory in Jamaica should 

 net a return equai to £ 2 per ton of tubers delivered at the factory, and 

 there should be a profit of ^ 8 per acre on good land under cas- 

 sava and economically managed. Cotton and cassava are suggested as 

 a good rotation. W. G. Freeman. 



Petersen, 0. G., Nattefrostens Virkning paa Bögens 



Ved. (Effet de la gelee nocturne sur le boisdu 



Hetre.) [Det forstlige Forsögsveesen. I.] Köbenhavn 



1904. p. 49—68. Avec 12 figures. 



Une gelee de Mai 1901 avait endommage les hetres dont les jeunes 

 pousses etaient tuees et les couches annuelles nouvelles rompues. 

 L'auteur a examine comment les plantes ont repare le dommage des 

 tissus et quelles en sont les consequences. Dans les ruptures il se 

 forme un tissu calloVde et c'est apres seulement que se continue la for- 

 mation du bois. En 1901 I'amidon etait peu abondant dans les arbres 

 endommages. O. Paulsen. 



Willis, J. C, Ceylon Agriculture and Economic 



Products in 1903. (Circulars and Agricultural Journal, 



Royal Botanic Gardens, Ceylon. Vol. II. No. 15. 1904. 



p. 209-216.) 



The general results of the year were satisfactory, for whilst the 

 exports of coffee and cinchona have continued their steady decrease, 

 the exports of cacao were siightiy below previous years, and citronella 

 oil was also low due mainly tu adulteration ; tea, cardamoms, cinnamon, 

 coconut products and rubber increased sufficiently to more than com- 

 pensate for these deficiencies. 



