l'"t ual Remarks. 53 



half the continent, as I have previously shown, but extends to 

 the Pacific coast and is found as far south as San Diego, showing 

 over this wide range absolutely no differences that would justify 

 varietal designation. All the characters are absolutely the same, 

 and the rather dark coloring of the horny and chitinous parts of 

 the body in the California, Dakota, and Colorado specimens 

 would indicate that the western forms have this peculiarity as 

 compared with the eastern. This species is now known to pol- 

 linize all the true Yuccas so far studied, and accompanies them 

 across the continent. It thus pollinizes Yucca filamentosa and its 

 several forms in the northeast; Y. gloriosa and F. aloifolia in the 

 southeast ; F. angustifolia (glauca) in the Rocky Mountain re- 

 gions; F. rapicola and F. data in the southwest ; and F. baccata, 

 which connects the territory of F. angusti/olia with that of F. 

 l>rc,r/J'of/(t, and F. wfiipplei. It thus occurs in the same territory 

 as its two congeners, Pronuba synthetica and P. macidata, with its 

 aterrima variety, while these last are restricted to their respect- 

 ive Yuccas. This fact, as Professor Trelease has pointed out, 

 strengthens the inference that brevifolia and ivhipplei are primary 

 Pacific coast types, while baccata is an immigrant from the east. 

 It remains yet to observe the pollinizers associated with Yucca 

 filifera, F. australis, F. treculeandj and F. guatemalensis, each of 

 which will probably have a distinct Pronuba, while the other 

 Yuccas not enumerated here will probably not have distinct 

 species connected with them. 



It would carry me too far to speculate further on the addi- 

 tional facts brought forth, but I would urge in conclusion that in 

 all Mr. Trelease's interesting observations in his special studies 

 of these different species of Yucca, and after having paid par- 

 ticular attention to the point, he has failed to see a single 

 Pronuba, in any species attempt to feed on either the stigmatic 

 secretion or the septal nectar. He was also unable to con- 

 vince himself that in any case the insect makes use of the 

 tongue in pollination, as he once thought it might. In this and 

 other respects he fully confirms the conclusions which I have 

 drawn in my previous communication to the Society, while the 

 additional data which I have indicated give further force to my 

 remarks upon variation, as exemplified by these Prodoxids. 



