Plate 1. 



4 '/' U 



K.. ;>. Mfliitosli oil its own roots. 



Fig. -i. Mclntosli on Oldenburg roots. 



(bMii-uri's .'3 and \ an on aiii>roxiinately tlie same scale. The aii])arent dift'erenee 

 in the si/.e of the screen is due to tiie fact tliat in Figure I tlie screen was held 

 considerahlv farther from tlie tree than in Figure .'5.) 



