NOTES AND ABSTRACTS. 



847 



abundant in the wood vessels. Death occurred during a •very dry 

 period following suddenly after a prolonged period of exceptionally 

 rainy weather. The author seeks to explain the matter by supposing 

 that during the wet period the supply of nutritive salts was a very 

 dilute one, and that thyloses were formed to function as " suckers " 

 to supply the wood parenchymia with salts. During this wet period 

 transpiration was naturally diminished and the choking effect of these 

 thyloses did not make itself felt. On the sudden return of hot weather 

 and consequent increased transpiration, however, the vessels were 

 unable to supply the necessary amount of water, and hence death 

 ensued. — G. H. P. 



Viola cornuta * Bupgrermeistep ' Dr. Reicke. By J. Klar 

 {Gartenflora, vol. hx. pt. xii. p. 263). — This Viola has a robust, 

 compact habit, and remains in flower a long time. — >S'. E. W. 



Watering- Can, New, ^'Jajag-." By F. Calva {Oester. Gart. 

 Zeit. vol. V. pt. V. pp. 188-190; 1 fig.). — To prevent the fine holes 

 in the rose of the watering-can getting choked a conical brass- wire 

 filter is inserted at the junction of the spout with the body of the can. 

 It can easily be taken out and cleaned when necessary. — aS'. E. W. 



Wikstpoemia indica, The Number of Chromosomes of. 



By E. Strasburger (Afin. Jard. Bot. Buit. 3rd supp. 1st part, 1910, 

 pp. 13-18; with 3 figs.). — The pollen mother-cells of Wikstroemia con- 

 tain twenty-six chromosomes (gemini). From this one would expect to 

 fmd fifty-two chromosomes in the vegetative tissues of the root, &c. 

 This, however, is not the case, smaller numbers being always met with. 

 Thus in two root-tips thirty and twenty-eight chromosomes were met 

 with. From the fact that these chromosomes vary considerably in size, 

 and also from their relative arrangement in the nucleus, Strasburger 

 concludes that certain of the chromosomes do not separate from one 

 another at the commencement of nuclear division, so that what appear 

 to be single chromosomes are really composite structures consisting of 

 two such bodies united together. In this way the author explains the 

 fact that the number of chromosomes actually met with in these 

 tissues appears to be smaller than would be expected on theoretical 

 grounds. — R. B. 



Windbreaks and Hedg-es. By C. B. Waldron {U.S.A. Agr. Exp. 



St. North Dakota, Bull. 88, 1910). — In order to protect farm crops, 

 hedges, and shelter-belts of various kinds are fully described, as also 

 the advantage to be derived from the use of them in arid and exposed 

 situations. — A. D. W. 



Wistaria sinensis. By E. Eipper (Oestr. Gart. Zeit. vol. v. pt. xi. 

 pp. 415-416; 1 fig.). — This "Wisteria should be planted in good soil 

 containing lime, old mortar, and well-rotted cow-dung. It likes a sunny 

 and rather moist situation. — S. E. W . 



