820 



MACROSCOPIC AND MICROSCOPIC CHARACTERS OF PLANTS. 



staminode of 0. spicerianum is narrower than that of 

 C. villosum; that of C. laihamianum is between those of 

 the parents but is nearer C. villosum; that of C. lathami- 

 anum inversum is of exactly the same width as in G. 

 villosum. (Table J 52.) 



The color of the staminode of C. spicerianum is 

 purple with a white margin and a yellow tubercle. In 

 C. villosum it is olive-green, with short purple hairs and 

 a greenish tubercle. In. C. lathamianum it is a greenish 

 purple with a white margin, with long purple hairs and 

 a green tubercle. In C. lathamianum inversum it is 

 purplish green, much more green than in C latham- 

 ianum, with long purple hairs and a small greenish 

 tubercle. 



Comparisons of the Microscopic Characters. 

 Leaf, 



Sections of the upper epidermis of leaves of the same 

 age (second youngest) from the four plants were made 

 at the apex, middle, and base. At the apex the cells are 

 hexagonal, with a thick cuticle. The cell-walls are not 

 nearly as thick in 0. spicerianum as in C. villosum; very 

 slightly thicker in C. lathamianum than in 0. spiceri- 

 anum; and slightly thicker in C. lathamianum inversum 

 than in C. lathamianum. C. lathamianum inversum is 

 therefore nearer C. villosum, and C. lathamianum nearer 

 C. spicerianum. The difference between the two hybrids 

 is very slight. 



The cells are much larger in C. spicerianum than in 

 C. villosum, and in both hybrids they are between those 

 of the parent cells, but nearer C. spicerianum in length 

 and nearer C. villosum in width. Comparing the cells 

 of the two hybrids, those of G. lathamianum inversum 

 are larger than those of G. lathamianum, thus resem- 

 bling those of C. spicerianum more than those of the 

 other hybrid. (Table J 53.) 



At the middle of the leaf the cell-walls are practically 

 identical in thickness in all four plants. The cells are 

 larger in G. spicerianum than in G. villosum; those of 

 G. lathamianum are between those of the parents though 

 in width much nearer G. spicerianum and in length 

 nearer C. villosum. The cells of C. lathamianum inver- 

 sum are larger than in either parent. (Table J 53.) 



At the base of the leaf, the upper epidermal cells are 

 smaller in C. spicerianum than in C. villosum. In C. 

 lathamianum they are larger than in either parent, and 

 the width of C. lathamianum inversum is greater than 

 in either parent. The length, however, is between those 

 of the parents, though much nearer C. villosum than 

 C. spicerianum. (Table J 53.) 



The average size of the upper epidermal cells of the 

 whole leaf is greater in C. spicerianum than in C. vil- 

 losum. The cells of the hybrids are wider than in either 

 parent, and though between the two parents in length are 

 much nearer C. spicerianum than C. villosum. Those of 

 C. lathamianum are longer and narrower than those of 

 C. lathamianum inversum. (Table J 53.) 



Sections of the lower epidermis were also examined at 

 the apex, middle, and base of the leaf. The lower epider- 

 mal cells at the apex are hexagonal or elongated-hexago- 

 nal, with somewhat thick walls and a thick cuticle. They 

 are shorter and broader in C. spicerianum than in C. 

 villosum. In both hybrids the width is between those 

 of the parents, though nearer C. spicerianum; the length 



in C. lathamianum is between those of the parents, but 

 nearer C. villosum; and in C. lathamianum inversum 

 the length is greater than in either parent. (Table J 53.) 



Stomata are present on the lower epidermis. At the 

 apex they number 8.3 in C. spicerianum, 9.2 in C. vil- 

 losum, 8.8 in C. lathamianum, and 7.4 in C. lathamianum 

 inversum. 



At the middle of the leaf, the lower epidermal cells 

 in C. spicerianum are shorter than in 0. villosum but of 

 almost the same width. In 0. lathamianum the length 

 is between those of the parents, but nearer that of C. vil- 

 losum; in C. lathamianum inversum the length is identi- 

 cal with that of 0. villosum. In both hybrids the cells 

 are wider than in either parent. (Table J 53.) 



Stomata at the midrib of the leaf are 8.2 in C. spiceri- 

 anum, 7.7 in C. villosum, but less numerous in both 

 hybrids than in either parent, although the number in 

 C. lathamianum (7.6) is almost identical with that of 

 C. villosum (6.4). 



The lower epidermal cells at the base of the leaf are 

 elongated hexagonal, with thick walls and a thick cuticle. 

 They are smaller in C. spicerianum than in C. villosum. 

 In C. lathamianum the length is greater than in either 

 parent, being only slightly longer than in C. villosum. In 

 C. lathamianum inversum the length, while between those 

 of the parents, is much nearer C. spicerianum. The 

 width in both hybrids is greater than in either parent. 

 (Table J 53.) 



Stomata are very rare at the base of the leaf, there 

 being 2.4 in C. spicerianum., none in C. villosum, 1.4 in 

 C. laihamianum, and 0.5 in C. lathamianum inversum. 



The average size of the lower epidermal cells for the 

 whole leaf is less in C. spicerianum than in C. villosum. 

 In both hybrids the length is between those of the 

 parents, though nearer C. villosum than C. spicerianum; 

 the width, however, is greater than in either parent. 

 (Table J 53.) 



The lower surface of the leaf at the base has large, 

 dull, purple blotches in C. spicerianum that are due 

 to many cells grouped together and filled with a red- 

 violet sap. C. villosum has small, dull, brownish-purple 

 dots due to groups of 5 or 6 cells being filled with a red- 

 purple sap. C. lathamianum has many dull-purple 

 blotches that are arranged in lines, and so close together 

 that the base is almost entirely dull purple. This is due 

 to a deep red-violet sap in groups of several cells. The 

 smaller purple spots in C. lathamia?ium inversum are 

 also clue to the same cause. 



Transverse sections of the leaves of the same age 

 were made midway between the apex and the base (Plate 

 34, figs. 202, 203, 204, and 205) and examined at the mid- 

 rib region. The upper epidermal cells are saipplied with a 

 thick cuticle, and with a layer of wax above it. The 

 cuticle is much thicker in C. spicerianum than in C. vil- 

 losum, but not as thick in the two hybrids as in either 

 parent. The cells are greatly elongated in depth, form- 

 ing an aqueous tissue. They are much deeper in C. 

 spicerianum than in C. villosum; between the parents in 

 C. lathamianum inversum though nearer C. villosum; 

 and shorter than in either parent in C. lathamianum. 

 (Table J 53.) 



The lower epidermal cells directly beneath the mid- 

 rib bundle were compared as to the thickness of the 

 outer wall and the size of the cells. The outer wall is 



