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STUDIES ON THE DISSEMINATION AND LEAF REFLEXION OF 
YUCCA ALOIFOLIA AND OTHER SPECIES. 
BY HERBERT J. WEBBER. 
The Yuccas or Spanish bayonets, since the discovery of 
their peculiar and unique methods of pollination, have 
become objects of very general interest and study. It is, 
however, to the long continued and painstaking researches 
of Drs. Engelmann,* Riley ¢ and Trelease { that we are the 
most indebted for the very complete information regarding 
this phase of the ecology of the genus which we now 
possess. 
The methods of dissemination in the various species of 
Yucca, while very interesting in many features, have as yet 
been very little studied. The only account that has come 
to the writer’s notice is that given by Dr. Trelease in 
the closing paragraphs of his paper on the ** Further Stud- 
ies of Yuccas and their Pollination.’’ § Here the adaptation 
of the different forms of Yucca fruits to different 
methods of seed dissemination is mentioned, and interest- 
ing observations are given on the dissemination of Yucca 
brevifolia and certain capsular species. 
* Engelmann, Geo., “The Flower of Yucca and its Fertilization.” 
Bull. Torr. Bot. Club, Vol. II. (1872), pp. 33-87.— “‘ Notes on the 
Genus Yucca.”? Trans. St. Louis Acad. of Sci., Vol. IIT. (1873), pp. 17-54. 
¢ Riley, C. V., ‘‘On a New Genus in the Lepidopterous Family 
Tineidae, with remarks on the Fertilization of Yucca.”? Trans. St. 
Louis Acad. Sci., Vol. III. (1873), pp. 55-69. — ‘“¢ The Yucca Moth and 
Yucca Pollination.”? Mo. Botanical Garden, 8rd Annual Report (St. 
Louis, 1892), pp. 99-158. 
t Trelease, Wm., “‘ The Nectary of Yucca.’’ Bull. Torr. Bot. Club, Vol. 
XIII. (Aug., 1886), p. 135. — “* Notes and Observations. I. Detail Ilus- 
trations of Yucca.’? Mo. Botanical Garden, 3rd Annual Report (St. 
Louis, 1892), pp. 161-168. — “ Further Studies of Yuccas and their Polli- 
nation.”? Mo. Botanical Garden, 4th Annual Report (St. Louis, 1893), pp. 
181-226. 
§ Trelease, Wm., l.c., p. 223. 
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