370 



this year, they have observed honey-bees about the Yucca flowers. It 

 is further corroborated by experiment which I made this summer of 

 confining bees to the flowers within a gauze inclosure. 



As for pollination by other insects, ChauUogaathus pennsylv aniens^ 

 which feeds on both pollen and the nectar, is the most common species 

 found in the flowers, and by virtue of these habits and its peculiarly 

 modified mouth-parts, is most to be suspected; yet I have carefully 

 watched it for years, only to be convinced that it never either assists or 

 competes with Prouuba in the act of pollination. 



3d. This argument has already been disposed of in my previous com- 

 munication (Vol 11, p. 238, summary iv), and it is only necessary to add, 

 that until Mr. Hulst is more exact, and will tell us what proportion of 

 his pods containing no larvae also showed no signs of oviposition 

 (/. e., how many were perfect without sign of puncture or constriction or 

 irregularity about the middle), we shall not even know how many the 

 little moth poUinized without getting a chance to perform the other (to 

 her) important -act. 



4th. This is contrary to my own experience in Europe, and to all au- 

 thoritative record familiar to me, and until Mr. Hulst gives us his au- 

 thority and the evidence, it were sheer waste of time to further discuss 

 the point. 



1 have thus disposed of all the valid arguments brought forward by 

 Mr. Hulst to sustain his position on this matter. I may briefly notice, 

 however, a little satire which he indulges in at my expense, and a quite 

 irrelevant assertion which hapi)ens also to be incorrect. 



As one deeply interested in apiculture and a practical bee-keeper 

 twenty-seven years ago, it was perhaj^s unpardonable in me not to 

 qualify the statement about bees not being attracted to white flowers. 

 Both Miiller, in his "Alpenblumen," and Lubbock, in "Ants, Bees, 

 Wasps," etc., have shown that bees prefer blue and purple to white 

 flowers, and this is what was meant on the face of my language, so to 

 speak; but Mr. Bulst has naturally made the most of the lapsuSj and 

 scored a point where every other point is against him. 



The assertion which I would call attention to, and which is entirely 

 beside the question at issue, is that '^ we are indebted to Dr. Engelmanu 

 for the discovery of the fact that Pronuba is an agent in the fertiliza- 

 tion of Yucca." 



Whatever may have led Mr. Hulst to make tbis assertion, it is sim- 

 ply untrue, and the facts, which I may as well put on record here, are 

 these : In June, 1872, Dr. Engelmann, who then knew full well that 

 Yucca needed extraneous aid in fertilization, called my attention to 

 this fact, and to the further fact that insects, especially white moths 

 and soldier-beetles {ChauUo(/nathns)^vi'eTe common in the flowers. He 

 made no observation whatever upon insect pollination, but wished me 

 to study the question. The discov^ery that Pronuba was the agent was 

 my own, as were all the subsequent discoveries in reference to the in- 



