1925] HOLM—CARYA AND JUGLANS 389 
PLATE XVI 
Juglans nigra 
Fic. 15.—Cross-section of primary root of young seedling a month old: 
C, inner part of primary cortex; End, endodermis; Co, pericambial cork; Ct, 
oa ona part of secondary cortex; X 320 
Fic. 16.—Inner part of same root (i. 15): C+, secondary cortex with 
strands of stereome (Si); L, leptome; Camb, daxcbiiti: P, outermost layer of 
pith; x32 
Fic. 17. te cross-sections of old lateral root; PR, parenchymatic ray; 
X 320. 
Fic. 18.—Cross-section of leaf: Ep, ventral, Ep+, dorsal epidermis; P, 
palisade tissue; P+, pneumatic tissue; 320. 
