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do not cause hayfever. The answer is found in their mode of 

 pollination. There are two ways in which the majority of flower- 

 ing plants are pollinated, viz. by insects (entomophily) and by 

 wind (anemophily). Plants which are insect pollinated and per- 

 fectly adapted to this mode of pollination cannot cause hay- 

 fever. Thus the orchids, milkweeds, sweet peas, and many 

 others of the more highly specialized flowers produce their 

 pollen in such a way that it remains in the flowers until re- 

 moved by the insect which is to carry it to another flower. But 

 by no means all insect pollinated flowers are so perfectly adapted 

 to entomophily as orchids, milkweeds and sweet peas. All stages 

 of imperfection in this adaptation are found. For example, if a 

 flowering branch of goldenrod is placed in water in the house, 

 after a few days pollen will be found scattered on the table 

 beneath the flowers. Out-of-doors this pollen, if not carried 

 away by insects, is blown away and even at times may become 

 a menace to hayfever sufferers; certainly it can easily be de- 

 tected on pollen slides far from the flowering goldenrods,. An 

 oustanding example of imperfect entomophily is found in the 

 willows. Some of the standard manuals of botany state that 

 willows are wind pollinated others that they are insect pol- 

 linated. Both are right; willow flowers are brightly colored, 

 sweet scented, provided with nectaries, and attract to them- 

 selves many insects which effectively carry their pollen from 

 flower to flower; so they are insect pollinated. On the other hand 

 their stamens are exserted and their pollen is not very sticky so 

 that, if it is not removed by insects, it is easily blown away by 

 the wind. Indeed willow pollen is often caught on pollen slides 

 several miles away from flowering willow trees; so they are 

 wind pollinated. Another example of such a dual method of 

 pollination is found in the red maple which appears to be about 

 equally wind and insect pollinated. The maples are not all alike 

 in this respect. In fact the several species comprise a nicely 

 graded series ranging from the Norway, Sycamore, and striped 

 maples which are entirely entomophilous, through the silver, 

 red and sugar maples which are both insect and wind pollinated, 

 to the three-leaved maple (Acer Negundo) which is entirely 

 anemophilous. As we pass along this series we note that the 

 flowers become less showy and attractive to insects but produce 

 more pollen and of a less sticky character. The flowers of the 



