PERIODICAL LITERATURE 



BOTANY AND ZOOLOGY 



In South Sweden there was cut down a 56- 



Grafting year-old pine that bore a fresh living branch of 



Spruce spruce of 51 years at 5 feet from the ground. 



on Pine . A nearer investigation showed that the spruce 



branch was really grafted on the pine in a natural 



way and has lived so without communication with the mother spruce 



at least fourteen years. 



Romell describes and pictures the anatomy of the juncture. The 

 coalescence surface has, microscopically seen, a very irregular shape. 

 The foreign cells must be almost jumbled together in the cambium. 

 The foreign cells are not, however, without influence on each other, 

 since the several spruce pores are always arranged so as to fall within 

 the area of the single corresponding pine pore. 



The whole forms an interesting case of formative correlation between 

 foreign tissues. The foreign cells, though to a large extent autonomi- 

 cally reacting in a morphological sense, react physiologically with each 

 other in a throughout harmonious way as parts of a single organism. 



Meddelanden Fran Statens Skogsforsoksanstalt. Haft. 16, Nr. 2-2, 1919, 61-66. 



The author throws some light on the occur- 

 Origin rence of the broad rays in oak with respect to 



of conditions of growth. By selecting vigorous and 



Pith Rays suppressed shoots from three different oaks and 



making microscopic sections of them, he ob- 

 served the following: 



"Both uniseriate and multiseriate rays are usually present in the 

 first annual rings, the latter radiating in pairs from each of the fine 

 lobes of the pith. In shoots of vigorous growth the multiseriate rays 

 are more numerous than in suppressed twigs, which gives added weight 

 to the theory that the broad rays have some relation to the amount of 

 food brought down for storage by the leaves. In suppressed twigs 

 the multiseriate rays may be entirely absent from the first 15 to 19 

 annual rings. 



"Multiseriate rays may arise at any point in the stem — not by a 



875 



