542 Agricultur, Horticultur, Forstbotanik. 



Sahara. Surface Irrigation is not practiced, the roots of the palms 

 finding their way to Underground water. Constant watchfulness is 

 necessary in order to prevent the gardens from being overwhelmed 

 by the shifting sand, the country being almost devoid of natural 

 Vegetation. The topography, climate, water supply and soils of the 

 region are discussed and brief descriptions are given of the cultural 

 methods used and of the principal varieties of the date palm grown. 



Trelease. 



Kearney, T. H., Date varieties and date culture in Tunis. 

 (Bull, XCII. Bureau Plant Industry, U. S. Department of Aafricul- 

 ture, 110 pp. 10 pls. 52 textfig. 1906.) 



Descriptions are given of the oases of southern Tunisia, 

 especially of the group known as the Djerid, where the best varie- 

 ties of dates are grown. Geography and topography, climate, Irrigation 

 and soils are treated at some length, especially in their relations to 

 date culture. The cultural methods used by the natives, including 

 the harvesting of the dates, are then discussed. The latter half of 

 the paper is devoted to descriptions of the principal varieties, 

 illustrated by outline drawings of the fruits and seeds, foUowed by 

 a descriptive key to the fruit characters of 48 varieties. 



The number of distinct varieties of the date palm occurring in 

 Tunisia is very large and many of them are extremely local. There 

 are more than 100 in the Djerid oases alone. Most of these are 

 very distinct, good characters being presented not only by the 

 fruits but by the fruit Clusters, trunks and foliage. The natives are 

 remarkably acute in recognizing the varieties even from the detached 

 young offshoots. In this paper the fruits only have been considered 

 in classifying the varieties, the characters chiefly used being shape, 

 size and color, character of the skin (whether smooth or wrinkled) 

 thickness and texture of the flesh, shape and size of the seed and 

 shape, size and color of the contents of the remarkable "giant cells". 

 These cells form a zone lying close to the skin and in the ripe fruit 

 contain highly refractive masses. The characters of these masses are 

 offen very useful for differentiating closely-related "< arieties, as they 

 sometimes differ extraordinarily in shape, size and color in varieties 

 that are otherwise almost undistinguishable. 



While the well-known Deglet Noor date is the only variety of 

 much commercial importance that is grown in Tunisia, there are 

 numerous others of fine quality and highly esteemed by the natives. 

 Chief of these is the extremely rare Menakher date, of which 

 there are perhaps not more than a score of trees in existence, 

 although the fruits at least equal in quality and greatly surpass in 

 size the Deglet Noor. Trelease. 



Ljung, E. W., Nägra undersökningar of ragens axbyggnad 

 och kärnkvalitet. [Einige Untersuchungen über den 

 Aehrenbau und die Kornqualität beim Roggen]. (Meddelande 

 frün Sveriges Utsädesförening. N^. 2. 34 pp. Malmö 1906.) 



r. Untersuchung über das Verhältnis zwischen dem 

 Korngewicht und der Zahl der Blüten im Aehrchen beim 

 Roggen. 



Um die praktische Bedeutung der Anzahl Körner, bezw. Blüten 

 innerhalb des Aehrchens zu entscheiden und andere damit verbun- 



