PERIODICAL LITERATURE 



BOTANY AND ZOOLOGY 



Hesselman, of the Swedish Experiment Sta- 



Dispersal tion, reports an interesting inquiry into the extent 



of Tree Pollen to which pollen of trees may be dispersed by 



winds ("sulphur rain"). The observations were 



made on board two fire-ships stationed some distance from shore, 20 



and 37 miles. At these distances the pollen rain was still quite extensive 



and the number of pollen sacks collected on small saucers was almost 



precisely in proportion to the distance. Pollen of alg?e are carried even 



to 200 miles. 



Since the characteristics of progeny are as dependent on the paternal 

 as on the maternal elements, the author points out the importance of 

 this wide pollen dispersal on the problem of seed supply. 



The influence of the far-reaching transport of pollen on fossil floras 

 is also discussed. 



lakttagelser over Skogstrddspollens Spridningsfornidga. Meddelanclen fran 

 Statens Skogsforsoksanstalt, Haft 16, Nr. .2-3, 1919, pp. 27-60. 



In tree-cutting in the crown forest Gullberg, in 

 Anatomy of the province Ostergotland, of south Sweden, there 

 Grafting of was cut down a 56-year-old pine that bore a 

 Spruce on Pine fresh, living branch of spruce of 51 years at 5 

 feet from the groimd. A nearer investigation 

 showed that the spruce branch was really grafted on the pine in a nat- 

 ural way and has lived so without communication with the mother 

 spruce at least 14 years. 



A real and efifective coalescence being thus physiologically proved. 

 the foreign tissues anatomically, too. are very intimately united. The 

 limit between the different tissues is sometimes undistinguishable, in 

 other cases marked by irregularities. There follows a detailed descrip- 

 tion of the anatomy. 



Anatomiska Egendomligheter z'id en Naturympning av Gran pa Tall. Meddel- 

 anden fran Statens Skogsforsoksanstalt. Haft 16, Nr. 2-3, 1919, pp. 61-66. 



79.^ 



