802 



MACROSCOPIC AND MICROSCOPIC CHARACTERS OF PLANTS. 



tween the parents in width, though very much nearer 

 C. eburncum. (Table J 27.) 



The color is an olive green with faint brownish lines 

 along the veins in C. lowianum; and ivory-white in C. 

 eburneum; and a pale yellowish-brownish-green with 

 reddish-brown lines along the veins in the hybrid. The 

 color is due to the presence of reddish-violet sap and 

 yellow chromoplasts in the cells in both C. lowianum 

 and the hybrid, and to very pale, yellowish chromoplasts 

 in C. eburneum. 



The lower epidermis of the dorsal sepal was also 

 examined at the median point. The cells are similar to 

 the upper epidermal cells, but do not differ so much in 

 the ratio of length to width. The cells are larger in 

 C. lowianum than in C. eburncum. In length, the cells 

 of the hybrid are between those of the parents, though 

 much nearer C. lowianum than C. eburneum; in width 

 they are almost identical with those of C. lowianum. 

 (Table J 27.) 



The upper epidermis of one of the lateral petals was 

 also examined at the median point. The cells are longer 

 and narrower in C. lowianum than in C. eburneum. In 

 the hybrid the length is almost exactly mid-intermediate 

 between the parents, while the width is slightly greater 

 than in either parent. (Table J 27.) 



The color of the petals is due to a red-violet sap and 

 yellow chromoplasts in C. lowianum and the hybrid, and 

 to pale yellowish chromoplasts in C. eburneum. 



The lower epidermis of one of the lateral petals was 

 also examined at the median point. The cells are longer 

 and narrower in C. lowianum than in C. eburneum. In 

 the hybrid they are almost identical in dimensions with 

 those of C. lowianum, being of the same width but of 

 slightly greater length. (Table J 27.) 



Sections of the upper epidermis of the anterior lobe 

 of the labcllum, over the colored area are reddish crim- 

 son in C. lowianum; pale yellow in C. eburneum; and 

 brownish red in the hybrid. The cells in all three plants 

 are papillose. The papillae are long, narrow, and pointed 

 in C. lowianum; short, wide, and blunt in C. eburneum; 

 and of all gradations in length, width, and pointed to 

 blunt tips in the hybrid, the average length, however, 

 being nearer C. lowianum than C. eburneum. (Table 

 J 27.) 



The red-crimson of C. Imrinn inn and the brownish red 

 of the hybrid are due to the epidermal papilla? being 

 filled with small, yellow chromoplasts, and also to some 

 of them containing a reddish-violet cell sap. The yellow 

 of C. eburneum is due to the papillae containing yellow 

 chromoplasts. 



Sections of the lower epidermis of the anterior lobe 

 of the labellum were also examined. The cells are hexa- 

 gonal in shape and have rather thick walls. They are 

 slightly shorter and wider in C. lowianum than in C. 

 eburneum, but smaller in the hybrid than in either 

 parent. (Table J 27.) 



The cells of the upper epidermis of the lateral lobe 

 of the labcllum are irregularly pentagonal, hexagonal or 

 rectangular in shape. They are longer and narrower in 

 C. lowianum than in C. eburneum; shorter in the hybrid 

 than in either parent; but between the two parents in 

 width, though nearer C. eburneum than C. lowianum. 

 (Table J27.) 



TABLE J 27. 



The cells are papillose, the papillae being long, nar- 

 row, and pointed in C. lowianum; short, wide, and blunt 

 in C. eburneum; and longer and more pointed than in 

 C. eburneum, and wider than in C. lowianum. In the 

 hybrid, the average length is nearer that of C. lowianum 

 than of C. eburneum. "(Table J 27.) 



The color of the upper surface of the lateral lobes of 

 the labellum is a very pale yellow, due to the presence 



