333 

 Union of Parts. 



We may likewise consider as due to local over-nutrition the con- 

 dition arising when a cylindrical branch becomes broad and flattened. It 

 then looks as if a number of branches had grown together; nevertheless, 

 this is only rarely the case, for almost always only a single branch is in- 

 volved which, by broadening its vegetative point, no longer has a vegetative 

 cone at its apex, but a comb-like vegetative surface'. 



In the illustration of a spruce fasciation here given (Fig. 47) we recog- 

 nise the fact that the broadened axis is a single unit, first by the continued 



Fig-. 49. Fasciation of Alnus glutinosa. 



I'X Tiatui-alsize. Aftei Nolibc). 



Spiral position of the needles, especially at / and 2, and further in the cross- 

 sections A and B (Fig. 48), of which the pith and wood form a single 

 connected, uniform surface, and do not show any possible coalescence of 

 many single adjacent rings, as must be the case where fasciation is produced 

 by the coalescence of many branches originally separated. This theor}"^ is 

 not changed by a consideration of the fasciation of the alder (Fig. 49), in 

 v,'hich, besides the unusually characteristic crook-like bending of the 



tJber Pflanzen-Verbanclerung-. Referat in Bot. Zeit. 1867, p. 232. 



