upper and lower epidermis respectively of a leaf of the 

 O,macrocarpus, and on plate 2, Figs. 2 and 3, we have 

 similar drawings made from the upper and lewer epidermis 

 of the O,oxycoccus. In each species the cells are large 

 irregular thick walled with ragged margins, showing no 

 differences whatever in structure. It is possible that 

 the stomata in O,macrocarpus are a trifle more numer- 

 ous, but even this is doubtful. 



The Stem. 



Plate 3, Pig. 1 is a portion of a transverse sec- 

 tion of a stem of O,macrocarpus, — showing (a) epidermis, 

 (b) periderm, (c) primary cortex, (d) cambium region, 

 (e) medullary rays and (f) pith cells. 



Pig. 2 of the same plate is a longitudinal section 

 of a stem of the same plant showing longitudinal views 

 of the cells. Plate 4, Pig. 1, is a portion of a trans- 

 verse section of a stem of O.oxycoccus, showing (a) 

 epidermis, (b) periderm, (c) primary cortex, (d) cambium 

 region, (e) medullarjr rays and (f) Pith cells. 



Pig. 2 of the same plate is a longitudinal section 

 of a stem of the same plant showing longitudinal view of 

 the cells present. 



By a careful examination of these two drawings, we 

 find various differences but none of which are of im- 

 portance. I think they are more apt to be due to the 



