162 Guayule. 



. 





DESCRIPTION OF PLATE 39. 



i. Chief (foliage) shoot and axillary bud. Medullary canals in both. 

 2-3. Successive planes through chief peduncular shoot, and axillary bud, field 



plant. All canals pass into bud. 



4-7. Successive planes from below upwards of an irrigated chief (peduncular) 

 shoot and axillary bud. Two medullary canals which have passed into the 

 bud branch to form four canals. 

 8. Secondary cortical resin-canals in old cortex. Tangential section. 



