34 



It may be remembered tliat at our meeting at Buffalo I produced 

 three capsules that had not been produced by this elaborate process, 

 but simply by my mere touching of the papillose apex with one of 

 the flower's own pollenifer(nis anthers. Prof. Riley was so sure that 

 the seed-vessels could not have been produced in that way, that 

 there must have been some insect agency unknown to me in addi- 

 tion to my work, that at the conclusion of my paper he asked per- 

 mission to cut open the cajisules, sure of being able to show the lar- 

 \ae in the frnit ; Init he found them not. I recall these matters to 

 show that I have not misapprehended the position our friends take 

 on this question. 



I now again exhibit numerous seed vessels from this plant of Yuc- 

 ca angustifolia in which no_ trace of larvae can be found ; and seed 

 vessels of Yucca Jilamentosa growing but a few yards from the other, 

 Avliich are infested by the Pronuha yuccasella, as this species always is 

 when it seeds at all. 



The history of the fruiting of the Yucca aiiijut<iifn(ia is as follows: 

 It flowered in 1875 but produced no fruit.*) In 1ST6 the early 

 flowers proving infertile, I apj)lied the flower's own pollen to the 

 apex of the pistil of the four last flowers that opened ; these pro- 

 duced the four capsules examined by Professor Riley as already 

 noticed. In 1877 noticing that the Pronuba abounded in the flowers, 

 no hand application was made, and there was no fruit. In 1878 the 

 flowers Avere again left to tlie insects witli no fruitful results. The 

 past season pollenization by hand was resorted to, and the numerous 

 seed vessels I exhibit followed. As the pollen Avas merely applied 

 to the papillose apex it shows that in this species the elaborate and 

 wonderful ingenuity of the insect in applying pollen as dcscril)ed by 

 our friend is wholly unnecessary. 



We now come to some extremely interesting consideration groAving 

 out of these facts. 



*) At the conclusion of this address, delivered at the Saratoga meeting of the 

 American Association, Prof. C. V. Riley made some remarks which unfortunately 

 I did not hear. The newspaper reports make him say that I was mistaken in the in- 

 sect I found in Yucca angustifolia, that it was not Pronuba yuccasella. I have called 

 Prof. Riley's attention to this, and have asked for a correct note of what he did say, 

 but have only the reply that he is "not answerable for a newspaper report." It 

 remains then only for me to say in reply to the 'newspaper report" that at the 

 outset of my observations on Yucca angustijolia, I sent one of the insects caught to 

 Professor Riley asking : 'Ig this certainly Fronuba yuccasella?''' and he replied 

 that it was. 



