MACROSCOPIC AND MICROSCOPIC CHARACTERS OF PLANTS. 



787 



LEAF. 



A comparison of the lateral branches of the parents 

 and hybrid (Plate 25, figs. 146, 149, 152) arising from 

 the axil of a leaf on the main stem show that the branch 

 of the hybrid is of greater length and more leafy than that 

 of either parent. I. coccinea has large, thin, cordate 

 leaves, somewhat hastate at the base ; the lamina 6 by 5.4 

 cm. ; the petiole 4.3 cm. long. /. quamoclit has thin pin- 

 nate leaves, the pinnae thread-like 27 lobes, the lamina 

 4.8 by 5.1 cm.; the petiole 3.1 cm. long. The hybrid has 

 deeply lobed, wider leaves, which are much firmer in tex- 

 ture than those of either parent 9 lobes ; the lamina 5.6 

 by 7.3 cm. ; the petiole 3.9 cm. Thus, though the hybrid 

 is fairly mid-intermediate in shape, length of the lamina, 

 and length of the petiole, the lamina is wider and the 

 texture is firmer than in either parent and there are also 

 marked protuberances at the base of the petiole. The 

 leaves of the hybrid remain green longer and are more 

 resistant to the attacks of insects than those of 7. coccinea 

 and I. quamoclit. By the beginning of October all of 

 the leaves of I. coccinea have fallen, except a few on the 

 short flowering branches. The older leaves of I. quamo- 

 clit have withered and only those on the newest branches 

 have remained green. At the same time all the leaves 

 on the hybrid are green, only a very few showing any 

 trace of brownish-red. 



FLO WEE. 



Flowers are borne in dichasial cymes : In /. coccinea, 

 7-flowered ; in 7. quamoclit, 1- to 2-flowered ; and in the 

 hybrid, 2- to 5-flowered. The peduncle in 7. coccinea is 

 thicker than the pedicle, much thinner in 7. quamoclit, 

 and only very slightly thinner in the hybrid. There 

 are many more flowers produced on the hybrid than on 

 either parent. The flowers of the parents and the hybrid, 

 natural size, are illustrated in Plate 25, figs. 147, 150, 

 and 153. (Table J 2.) 



TABLE J 2. Sizes and colors of flower-parts. 

 I. coccinea: Flower-stalk 6.1 cm.; salver tube 2 cm.; diameter of 



corolla limb 1.6 cm.; diameter of tube opening 0.3 cm. 

 Color of outer tube yellow-orange to orange-red. 

 Color of upper surface of corolla limb vermillion with yellow 



center. 



Shape of corolla limb, 5-rounded lobes. 

 Calyx, length of awns, 3 to 4 mm. 

 Stamens: Length of filaments 2.4 cm.; color of filaments white; 



color of anthers greenish-white. 

 /. quamoclit: Flower-stalk 2.6 cm.; salver tuber 2.6 cm., diameter of 



corolla limb 1.6 cm.; diameter of tube opening 0.4 cm. 

 Color of outer tube reddish-pink. 

 Color of upper surface of corolla limb crimson. 

 Corolla limb-shape, 5-pointed star. 

 Calyx, not awned. 

 Stamens: Length of filaments 2.4 cm.; color of filaments pink 



near base becoming deep crimson at top; color of anthers 



crimson. 

 /. tloteri: Flower-stalk 8.8 cm.; salver tube 3 cm.; diameter of corolla 



limb 2.8 cm.; diameter of tube opening 0.5 cm. 

 Color of outer tube vermillion-red. 

 Color of upper surface of corolla limb scarlet. 

 Shape of corolla limb, 5-pointed, almost hexagonal. 

 Calyx, short awns, 2 mm. 

 Stamens: Length of filaments 3.4 cm.; color of filaments white 



at base becoming scarlet-pink at top ; color of anthers pale pink 



Though the flower in the hybrid is much larger than 

 in either parent, it is of a mid-degree of intermediateness 

 in the shape of the corolla limb, in the shape of the sepals, 

 and in the color of the corolla and stamens. 



FBTJIT. 



The fruit is a capsule, many of which mature on one 

 flower stalk in 7. coccinea; usually only 1 (very rarely 

 2) matures in 7. quamoclit; and usually 1 (very rarely 2) 

 matures in the hybrid. The capsule is subglobose in 

 7. coccinea, 7 by 9 mm. ; ovate in 7. quamoclit, 9 by 7 

 mm. ; and very broadly ovate in the hybrid, 8 by 6 mm. 

 The number of seeds matured in a capsule in 7. coccinea 

 is usually 4, rarely 2 or 1 ; in 7. quamoclit usually 2, 

 sometimes 3, more rarely 4 or 1 ; in the hybrid usually 

 1, very rarely 2 or 3. 



The seeds of the hybrid are intermediate in length 

 or height, but wider than in either parent, the greater 

 width probably being due to the absence of crowding in 

 the capsule. The seeds measure 3 by 3 mm. in 7. coc- 

 cinea; 5 by 2 mm. in 7. quamoclit; and 4.5 by 3.5 mm. 

 in the hybrid. 



Although many more flowers are produced by the 

 hybrid than by either parent, a smaller percentage of 

 them in the hybrid develop fruit than in either parent; 

 and a very small proportion of the seeds of the hybrid 

 germinate. 



COMPABISONS OF THE MICROSCOPIC CHABACTEBS. 

 COTYLEDONS. 



The cells, glands, and stomata of the epidermis of 

 the cotyledons are exactly like those of the leaf, and they 

 are described under the heading, " Mature leaf," page 

 789. Examinations were made with a Bausch and Lomb 

 2 in. ocular and 4 mm. objective; magnification 205 

 diameters. (Table J 3.) 



TABLE J 3. Cells, glands, and stomata of cotyledons. 

 Upper epidermis: 



/. coccinea: Cell walls wavy; cells 83.5 by 48/i; 1 gland in 5 fields; 



size of glands 3,v ; 6.6 stomata in a field ; size of stomata 3Sju. 

 7. yuamoclit: Cell walls not so wavy as in I. coccinea; cells 74.5 



by 49.5/j; 1 gland in 10 fields; size of glands 34.5/j; 9.4 



stomata in a field; size of stomata 33. SM- 

 /. sloteri: Cell walls between the parents in waviness; cells 95.5 



by 61. SM; 1 gland in 8 fields; size of glands 40.5/i; 5.7 stomata 



in a field; size of stomata 49/t. 

 Lower epidermis: 



/. coccinea: Cell walls not as wavy as in I. quamoclit; cells 77.5 



by 30/u; 1 gland in 4 fields; size of glands 35/j; 15.8 stomata 



in a field; size of stomata 34. 2p. 

 /. quamoclit: Cell walls very wavy; cells 69 by 36ju; 2 glands in 



1 field; size of glands 30.5^; 13.7 stomata in a field; size of 



stomata 33.8/1. 

 /. sloteri: Cell walls between the parents in waviness; cells 92 



by 50. SM; 1 gland in 2 fields; size of glands 39^; 7.4 stomata 



in a field; size of stomata 47.5/1- 



In the hybrid the cell walls are intermediate in 

 waviness, and the number of glands present is interme- 

 diate between those of the parents; but the stomata are 

 less numerous and larger, and the glands and cells are 

 larger, than in either parent. 



ROOTS. 



Transverse sections of the roots of 7. coccinea, I. 

 quamoclit, and 7. sloteri were taken at regions of the 

 same age. In the three the epidermis had been entirely 

 removed by sloughing. 



There have been developed 3 cork layers in 7. coc- 

 cinea; 3 to 4 in 7. quamoclit; and 3 in the hybrid. The 

 cork cells of the hybrid are much larger than in either 

 parent. (Table J 4.) 



