NOTES AND OBSERVATIONS. 165 
Plate 10. Y. filamentosa. — Plants blooming in the Mis- 
souri Botanical Garden, June, 1891. 
Plate 11. Y. Whipplei. — Plants beginning to bloom, 
< a, from a photograph by Parker, Apr. 13, 1876, near 
San Diego, Cal. 
Plate 12. Y. Whépple?.— Plants in full bloom, X »':, 
from a photograph taken near San Luis Obispo, Cal., in 
1873, by Dr. W. W. Hays. 
Plate 44. Y. aloifolia. —1. Stamen and pistil, x 2; 2, 
ends, and 8, side view and section, of fruit, natural size ; 
4, sections of seed, X 2. — After Engelmann. 
Plate 45. Y. Yucatana.—1, Habit, after a sketch by 
Schott in 1865; 2 and 3, flowers, natural size; 4, stamens 
and pistil, x 2; 5, leaf margin, x 15. — After Engel- 
mann. 
Plate 46. Y. macrocarpa. — Two fruits, natural size. —- 
After Engelmann. 
Plate 47. Y. Treculeana. — 1, Flower, natural size; 2, 
stigma, X 2; 3, fruit, and 4, cross section of same, natural 
size; 5, sections of seed, X 2. — After Engelmann. 
Plate 48. Y. baccata.—1, Stamen and pistil, natural 
size, and cross section of ovary, X 2; 2, fruit, natural 
size; 3, sections of same, reduced one-half ; 4, sections of 
seed, X 2.— After Engelmann. 
Plate 49. Y. brevifolia.—1, Margin of leaf, x 15; 2, 
pistil, natural size; 3, stamens, X 5; 4, fruit, and 5, end 
view of same, natural size; 6, sections of seed, X 2.— 
After Engelmann. 
Plate 50. Y. gloriosa.—1, Flower, natural size; 2, 
pistil and cross sections of same, X 2; 3, fruit, and sec- 
tion of same, natural size (from photographs of the Wash- 
ington fruit of plate 7, 6); 4, sections of seed, X 2.— 
After Engelmann. 
Plate 51. 1-4, Y. rupicola; 5-7, Y. angustifolia. —1, 
Symmetrical capsules, natural size; 2, section of seed, 
< 2; 3, margin of leaf of var. rigida, X 15, and 4, prom- 
inence of same, X 75.—5, Stamens and pistil, natural size; 
