412 



UPIEDINEAE. 



with resin, and as the same process goes on in bast and rind, 

 the turpentine overflows from fissures or wounds in the bark. 

 During the summer the mycelium grows amongst the dividing 

 cambium-cells and kills them. Where this occurs the year- 



FiG. 246. — Fci-idennium pint (corticota). 

 Youug twig bearing numerous aecidia. 

 (v. Tubeuf phot.) 



Fig. 245. — Peiidei-vihim pini (cortkola). 

 Branch and lateral twigs distinctly 

 swollen where attacked. They also bear 

 aecidia. (v. Tubeuf phot.) 



ring ceases to thicken, but as the mycelium seldom succeeds 

 during the first year in killing the cambium all round a 



