166 MISSOURI BOTANICAL GARDEN. 
6, symmetrical capsule, natural size; 7, sections of seed, 
x 2.—After Engelmann. 
Plate 52. Y. filamentosa. — 1, Sections of pistil at various 
heights, showing connection of stigmatic chamber with 
ovarian cells, X 2; 2, stigma, X 3; 3, stamen before and 
after dehiscence, enlarged; 4, Rronuba larva in situ in 
nearly mature capsule, natural size; 5, young ovules bored 
by larva, enlarged; 6, capsule (too symmetrical) after es- 
cape of larve, natural size; 7, seed and sections, < 2; 8, 
developing egg of Pronuba, X 30.—1 and 5 to 8, after En- 
gelmann ; the remainder from nature by Miss Johnson. 
Plate 53. Y. filamentosa.—1, Pistil at time of fertiliza- 
tion, in longitudinal section, showing on the right develop- 
ment of pollen tubes through the stylar channel into ovary, 
and on the left the septal nectar gland A, with its duct, B, 
and outlet C, x 5; 2, part of cross section at A B, show- 
ing below, the outer portion of septal gland, and above, the 
duct B and its outward closure by the surface papille of 
ovary, X 75; 3, pollen tube, x 150; 4, emergence of same 
from extine of pollen grain, and 5, distal end of same, show- 
ing the not infrequent occlusion of cell cavity, both x 400; 
6, apex of ovule in longitudinal section, showing egg ap- 
paratus and entering pollen tube, X 400.—3 and 4 after 
Engelmann, the remainder from nature by Mr. Webber. 
Plate 54. Y. Whipplet.—1, Section of flower, and 2, 
side view of pistil,—from the Gardeners’ Chronicle; 3, 
pistil, 4, section of stigma, 5, section of ovary, and 6, 
stamen, enlarged; 7, capsule, natural size; 8, sections of 
seed, X 2. — After Engelmann. 
W.T. 
