(^H. IV, 1'^ 



MONSTROSITIES OF STEMS 



199 



■fi 



Spruces and some other trees. Here, instead of the usual 

 development of a few buds with inhibition of others, many 



or all of the buds on the ^ , .-,-rr-^~=~-_ 



branches affected develop 

 equally, and more or less 

 independently of the 

 others. It is known 

 that this condition ih 

 produced by the pres- 

 ence of a parasite, the 



obvious effect of which Orange 

 , , , graph.) 



IS to paralyze the mech- 

 anism of growth correlation by which the buds are ordinarily 

 controlled. 



Closel}^ analogous to these cases in buds is the unregulated 

 groicth of tissues. Thus, the large burls or gnarls which ap- 



Fiu 



146. 



A t\viii-fruit, of JMandarin 

 (Drawn from a photo- 



FiG. 147. — A t}'pical Witches' Broom, caused by an -Ecidiuni, a Fungus, on 

 a branch of Fix. (From Kerner.) 



