Pflanzenchemie. — Angewandte Botanik. 653 



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Man darf also annehmen dass ungefähr ein Fünftel bis mehr 

 als ein Viertel des gesammten Volumens des Holzes aus stärkehaltigem 

 Speichergewebe besteht. Bezüglich des Stärkegehaltes (nach Gewichts- 

 procenten) sowie des Fettgehaltes des Holzes zitirt der Verf. die 

 Angaben anderer Autoren. Von aktueller Bedeutung ist dann die 

 Beantwortung der Frage, in wie weit diese Reservestoffe des Holzes 

 vom Menschen verdaut werden können. Es ist dies letztere nur 

 möglich, wenn alle Zellwände zerrissen und das Holz zu feinstem 

 Mehl gepulvert wird. Das gleiche gilt auch für die Verdauung des 

 Holzes im Magen des Pferdes und Rindes. Neger. 



Boyle, H. H., The Siamese Pomelo. (Journ. of Heredity. V. 

 p. 440—444. 1914.) 



For many years, horticulturists throughout the world have 

 heard stories of a wonderful seedless pomelo {Citrus decurnana) in 

 Slam, which was reputed to be finer than anything eise of that 

 sort known to science, but which for some reason, always seemed 

 to elude the long grasp of the men who are engaged in the work 

 securing new plants for breeders in the various tropical and sub- 

 tropical regions. An introduction of some plants into America in 

 1902 failed to give result for the only plant that arrived alive 

 showed to bear fruits which contained more seed than the ordinary 

 seedy pomelos of the United States; above this the rind, instead 

 of being a quarter of an inch thick (the average of United States 

 pomelos) was at least an inch thick. The writer has now again 

 visited Siam to study this pomelo and has obtained budwood, 

 plants and fruits, so that the plant is now established in the Phi- 

 lippine Islands and has been introduced to the United States. 



In some cases the author found on trees bearing seedless fruits, 

 also some seedy fruits, particularly on trees that stood on the side 

 of the grove nearest the ordinary, seminiferous pomelo trees. The 

 native gardeners believe that the seedlessness of their pomelos is 

 due to the use of salt, a coconut shell füll of which is placed around 

 the roots of each tree planted, while brackish water which backs 

 up between the levees, upon which the trees stand, is used for 

 irrigation. The writers investigations convinced him that we have 

 to do with genuine seedless types, which however are capable of 

 producing seeds when cross-pollinated. On this theory, the occasional 

 seedy fruits there produced are the result of poUen from trees in 

 the adjoining orchard, carried by the wind or insects to the nor- 

 mally seedless trees. Similar results were reported by Webber 

 a. o. on navel oranges, that are normally seedless, but contain 

 seeds when poUinated with pollen from various other varieties of 

 Citrous fruits. 



The seedless pomelos of Siam are classified by the writer into 

 4 types, which are quite distinct in size, colour, form, taste a. o. 



M. J. Sirks (Haarlem). 



Griffiths, D.. Hardier Spineless Cactus. (Journ. of Heredity, 

 VI. p. 182-191. 1915.) 



The main problem associated with spineless prickly pear cul- 

 ture today is to increase the resistance of these plants to low tem- 

 peratures. 



Hardy native species of the United, more particularly of cen- 



