NOTES AND OBSERVATIONS. 
1. DETAIL ILLUSTRATIONS OF YUCCA, 
During the time that I have resided in St. Louis, I have 
many times had occasion to observe the principal facts con- 
nected with the pollination of Yucca jfilamentosa and the 
forms referred to that species by Dr. Engelmann, and to 
demonstrate them to visitors tothe Garden. The Chairman 
of the Garden Committee of the institution, who viewed 
them in my company last spring, was so impressed with 
their interest that I made a short visit to the Rocky 
Mountains early in July last, for the purpose of making 
similar observations on Y. angustifolia, with the intention 
of summarizing for the present volume all that was known 
on the subject. On my return I found on my table a letter 
from Professor Riley, to whom, and Dr. Engelmann, the 
discovery and elaboration of the curious facts is due, 
offering to prepare for this report a paper such as I had in 
mind. Asan account from his pen promised far greater 
completeness and interest than I could have hoped to attain, 
his offer was very gratefully accepted, and the article 
appears in the preceding pages. 
While reviewing the material at the Garden bearing upon 
Yueca, I found a large number of drawings by Dr. Engel- 
mann, which I had intended utilizing in connection with my 
paper; and as these sketches depict the floral and capsular 
structure of some species that have as yet been inadequately 
figured, I have had them redrawn in ink by Miss Grace E. 
Johnson for photo-engraving, and publish them herewith. 
I have included with them reproductions of photographs 
showing the habit of growth of several species, and also 
some figures illustrative of our observations on Y. fila- 
mentosa, which had been prepared before the receipt of 
Professor Riley’s paper, and may prove of interest in 
connection with it. 
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