NOTES AND OBSERVATIONS. 145 
southeastern Texas, I met Mr. Samuel T. Tyson, a mining 
engineer, of Mapimi, Mexico, who became sufliciently in- 
terested in the subject to promise to observe wikis could 
on the arborescent Yuccas of the mountains of Durango, 
and about the middle of April I had the satisfaction of 
receiving from him several specimens of Pronuba obtained 
from the flowers of the common “ Palma ”’ of that region, 
which is described as having an upright panicle, and is 
evidently the same as the Carneros Pass specimens of Mr. 
Pringle, which have generally been referred to the present 
species.* The moths, the females of which were abun- 
dantly laden with pollen balls, and concerning the activity 
of which in the pollination of this species there can be no 
doubt, though they were not actually observed at work, 
prove to be Pronuba yuccasella. This moth, therefore, is 
shown to be the active agent in the pollination of Yuccas 
from Florida northward as far as fruit is set as a result of 
Pronuba activity, westward as far as southern California, t 
and into the mountains of northern Mexico, to the south.t 
Whether, as Professor Riley surmised,§ Y. Treculeana, 
lying in the region between Southwestern and Mexican 
species not known to be pollinated by P. yuccasella, and 
Y. filifera, the ‘“‘ Palma de San Pedro,”’ occurring in 
northern Mexico with Y. macrocarpa, but, as Mr. Tyson 
writes, blooming later than the latter, more dependent 
upon the rains, and consequently more variable in its time 
of flowering, are pollinated by distinct species of moths, 
remains to be shown by direct observation, but so far as 
the former is concerned, this is doubtful. 
Y. brevifolia, Trelease, Rept. 4: 193-9. pl. 6-9, 21, 
becomes, for reasons of priority, Y.arborescens, Trelease,— 
Sargent, 7. c. 10: 19-21. pl. 502. 
* Trelease, 1. c. 4: 191.— Sargent, 1. c. 10: 14. 
t+ Trelease, Rept. 4: 222. 
t The Mexican specimens here referred to have been deposited in the 
National Museum. 
§ Rept. Mo. Bot. Gard. 8: 121, 122. 
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