42 THE AMERICAN BOTANIST 



is exquisite, refreshing, useful and necessary in the plant 

 world. 



It is when the grains are considered individually, those 

 known to be wind wafted and those borne by insect agency 

 that we begin to realize their wonder. It is very essential 

 that there should be some means by which a wind carried 

 grain should easily catch the wind and we find in numbers 

 and numbers of instances that such grains often possess many 

 sides and angles. In form they are triangular, square, polyhe- 

 dral, hexagonal, octagonal, cubical, filiform cylindrical, etc. 

 So, too, it is extremely light in weight, very thin coated, very 

 smooth surfaced and very dry and powdery. On the other 

 hand, insect borne grains are usually circular, oval, ellipsoid, 

 etc. in form, their coats are marvelously grooved, warted, 

 pitted, furrowed, ridged or covered with most exquisite spin^. 

 ous projections or excrescences. They are often extremely 

 mucilaginous, owing to wee drops of oil that are secreted, this 

 oil varying in color from cream to yellow and other richer 

 hues. Many grains are pearly white, shell pink, cream, very 

 pale green, lemon yellow, orange, rich red (as in some of the 

 mulleins), deep purple (in ai-bor vitae), almost black (some 

 tulips), blue (Scilla), brownish black (poppy) and of many 

 other varying tones, the commonest of all perhaps, being 

 deep yellow. 



Some very pretty and interesting examples may be seen 

 in the following plants : In the hazel a plant in which the 

 stamens are borne in pendulous delicate catkins, each grain 

 is triangular with a thickened portion at each angle : in arbor 

 vitae, another wind fertilized plant, the shape of the grain is 

 almost exactly similar though the coloring is different the 

 latter being purple and the former yellow. In the white 

 stitchwort the "dairy maids" of our spring hedgerows the 

 grain is hexagonal, yellow and very rough coated. In mallow 

 it is circular, having its outer coat (extine) studded' over 

 with most exquisite delicate spinous projections and of a deep 



