35 



Pi'onuha yuccusdlu^ tlie Yucca motli, has for years abounded on my 

 flowers of the Vacca Jilaiiieiilosa. It has not been known to visit 

 any other plant than Yucca. Yucca amjustifoUa begins to flower from 

 three to two weeks and its blossoming is all over before Yucca Jila- 

 mentosa begins to open. The facts now adduced show that the 

 moths exist weeks before the flowers bloom with Avhich they have 

 been so intimately connected, feeding of course on other flowers, and 

 would perhaps make use of other fruits as depositaries for their eggs 

 if Y'ucca should not exist. At any rate the facts weaken any belief 

 we may have that the Y^ucca and Y^'ucca moth through tlie long 

 ages, have become mutually adapted to each otlier tl\roug]i a fancied 

 mutual bench t. 



But the fact remains tliat the Y^ucca is so arranged that it must 

 have external aid before it can use pollen ; and it is believed that 

 this arrangement is for the express purpose of facilitating the 

 introduction of strange pollen ; and further that this arrangement 

 must lie useful, or it would not exist. And then it is assumed that 

 this useful purpose can only be understood by believing that cross- 

 fertilized seed is of the most benefit to the race. Let us examine 

 this reasoning in the light of facts: — 



In 1871 I found Yucca an rjusf {folia seeding abundantly in Colorado; 

 but wdien the interesting matters in its history were brought out l)v 

 Prof. Riley, I could not remember whether the seed vessels were infested 

 by the larvae of the yucca moth, and was glad to revisit Colorado in '73 

 to examine the plants; but I did not find one seed-vessel in several 

 weeks search for tliem. 1 have since engaged friends to get me some, l)ut 

 none have found them. In order to test the matter thoroughly I engaged 

 with a professional seed collector in Southern Utah to buy of him 

 a pound of seed of each of the several species, and recently I liave 

 heard from him — the third successive year, that no plant within bis 

 observation has produced a single seed. How can we believe that 

 this elaborate arrangeme'nt for producing seeds by cross-fertilization 

 through insect agency is for the purpose of producing a lietter class 

 of seeds, when we see in many cases plants utterly fail, even for 

 successive years, to seed at all? 



We know that it is not to the interest of the individual to pro- 

 duce any seeds. Seed is a provision of nature looking to tlie good 

 of the future, and to which the present good of the individual is 

 often sacrificed. The JVlignonette, the Petunia, the Gaillardia, and 

 many other plants under garden culture, live for years when prevent- 



