differences in sizes of the two stems than real dif- 

 ferences of structure. The greatest difference is noti- 

 ceable in the cortical region. In O,oxycoccus, the 

 cells are smaller and more compact than in the 0, macro- 

 carpus. 



The dividing line of xylem and phloem is also more 

 distinct in the former. 



The longitudinal sections also show differences, but 

 comparisons of longitudinal sections are hardly fair 

 since it is difficult to take two even from different 

 stems of the same plant and make rigid comparisons. 



Leaves. 



Plate 5, Fig. 2, a portion of a transverse section 

 through the median vascular bundle of a leaf of 0, macro- 

 carpus, (a) upper epidermis, (b) palisade cells, (c) 

 xylene (d) phloem, A (f) lower epidermis, (e) parenchyma. 



Plate 6, 3?ig. 2, a portion of a transverse section 

 through the median vascular bundle of a leaf of 0,oxycoc- 

 cus, (a) upper epidermis, (b) palisade cells, (c) xylene, 

 (d) phloem, (e) parenchyma, (f) lower epidermis, (g) 

 crystal. 



By a careful study of these two drawings, one will 

 readily see how very much they resemble one another. 

 Aside from the difference in size of the bundles, one 

 could hardly recognize any difference whatever. 



