Guests Welcome and Unwelcome 245 



It is interesting to watch the methodical way in 

 which a humble-bee visits and explores a spire of fox- 

 glove, always beginning with the lowest bell and 

 working upwards ; but it may not have occurred to 

 all of us that, if she reversed her operations, the 

 foxglove's hope of cross-fertilization would be gone. 

 So it is, however ; for the foxglove-blossoms not only 

 open gradually, beginning with the lowermost, but the 

 pollen is ripe before the pistils are ready for it ; and 

 consequently the pistils of the lower blossoms are 

 waiting for pollen their own being safely gone 

 while the anthers of the upper blossoms are dis- 

 charging it. If the bee began at the top, she would 

 only bring to the pistils pollen from the upper blos- 

 soms on the same stalk; whereas, leaving off at the 

 top, she carries pollen away to the lowest blossoms 

 on the stem of another plant. 



Such are a few, and only a few, of the many marvel- 

 lous provisions for ensuring fertilization, for preventing 

 self-fertilization, for promoting cross-fertilization, and 

 for preventing the robbery of pollen and nectar by 

 insects which would not benefit the plant ; and to 

 conclude with the words of Professor Asa Gray : 



' If these structures and their operations do not 

 argue intention, what stronger evidence of intention 

 in nature can there possibly be ? If they do, such 

 evidences are countless, and almost every blossom 

 brings distinct testimony to the existence and pro- 

 vidence of a Designer and Ordainer, without whom, 

 we may well believe, not merely a sparrow, not even a 

 grain of pollen, may fall.' 



