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agaiustall influences, siicli as the condition oftbe plant and tbe weather, 

 which might affect or vitiate the results. These may be summed up 

 thus: 



(1) Dr. Euglemauu's limit of time during which fertilizations may 

 take i)hice must be extended so as to include the second evening, and 

 even the second morning, after the opening of the flower. 



(2) No seed has been produced, by merely touching the apices of the 

 stigma with the pollen, though partial fertilization may take place and 

 cause the growth of the fruit for a varying period, generally only three 

 or four days. When the pollen is thrust into the tube (the mode of 

 conveyance making little difference) fertilization is much more certain, 

 but even here is rarely sufficient to produce ripe seed, the upper part of 

 the pod often filling well, but the basal part not filling, and at last 

 withering, so that the fruit ultimately falls off" before ripening. 



The conclusion is inevitable that angustifoUa is more susceptible to 

 artificial pollination than the species which I experimented with, and 

 that Pronuba far excels man in the perfection with which she performs 

 the act. She has the power of fertilizing all the ovules, at which no 

 one will wonder who has carefully watched her, because the act of pol- 

 lination is normally repeated several times, first from one of the angles 

 between the apices, then from another, and, as Prof. William Trelease 

 has shown, the tongue is used, in addition to the tentacles, to push the 

 pollen down to the bottom of the tube. 



2d. I have made careful search the jiast summer, and have had my 

 associates, Messrs. Howard, Pergaude, and Lugger, assist in the search 

 for honey bees in or about the Yucca flowers in Washington. There 

 were over two hundred stalks under observation, most of them of easy 

 access, on the grounds of the Department of Agriculture. Keither of 

 the three gentlenn n mentioned detected any bees, but I succeeded on 

 two occasions, and each time between 9 and 10 a. m., in tindinga single 

 bee flying about the flowers. In neither case did the bee ma,ke anj^ at- 

 tempt to enter, but in each it probed around tbe outer base of the flower 

 in search for nectar, and soon left evidently without being able to get 

 much. These facts I record not iu any way to cast discredit on Mr. 

 Hulst's statement, but rather to show bow very different from his own 

 has been my experience in this direction, both iu St. Louis and Wash- 

 ington. Not that I placp! much faith in the constancy of bees, which 

 are known to be somewhat tickle in their tastes according to season or 

 colony, a fact that may account for the difference in our experience, as 

 may also tbe presumption that Apis meUifica is more abundant in 

 Brooklyn than iu Washington, or, again, the known fact that Yucca an- 

 f/ustifolia is less scant in nectar than its filamentose congener. Be that 

 as it may, our Apis has plainly, so far as observed, been after nectar, 

 and has shown no disposition whatever to go near tbe stigma, and this 

 fact is, as I have learned, corroborated by Professors Cook and Beal, 

 of the Michigan State Agricultural College, where, for the first time 



