THE AM-^RICAN BOTANIST 43 



brownish yellow color. X'ery choice examples of spinous 

 surfaced grains can be seen in many of the compositae for 

 instance, oxeye daisy, purple erigeron, common daisy, the 

 large white "moon" of our gardens, the marigolds, dandelion, 

 etc., and in the French honeysuckle, Campanulas and countless 

 other plant species. In the sweet scented mimosa each grain 

 is more or less octagonal having its surface covered with fur- 

 rows and intricate striations. In the chickory we find poly- 

 hedral grains, in the beech, oblong and d'eeply grooved ones, 

 in the plantain they are quite circular, smooth surfaced and 

 pearly white. In the lesser celandine they are circular, yel- 

 low in color, having here and there on their extines small 

 knob-like projections. The garden lupine shows a pretty ex- 

 ample : in this plant each grain is brick-shaped, somewhat 

 rounded at both ends, rather rough surfaced of a fair size 

 and rich orange in color, and in the stinging nettle we find 

 them quite circular in form, very smooth, grayish white in 

 hue and very small. It is interesting to take in one's fingers 

 a small branch of nettle blossoms and hold it up against a 

 dark object: if the stamens are ripe, that is, are ready to de- 

 hisce and shed their pollen the grains may be seen forcibly 

 ejected every now and then just like puffs of smoke. When 

 this happens in the open air, of course the wind catches the dry 

 powdery grains as they are thrown off from the somewhat 

 pendulous sprays and carries them to some other flower on 

 the same or a neig'hboring plant. In the cycaid's, firs, etc., all 

 of them wind fertilized plants, the grains of pollen are made 

 specially buoyant by reason of their possessing two very small 

 bladderlike pouches or hollow vescicles which act like sails. 



In all the flowering plants of field down, and hedgerow, 

 copse, woodland, river an'd swamp, can these lovely grains of 

 pollen dust be found — perfect little structures, each with two 

 cons surrounding a mass of coarse grandular protoplasm, the 

 life-giving element of all cells with its nucleus and grains of 

 starch, certain fatty matters and tiny drops of oil, all of which 



