POLLEN GRAINS 49 



is immaterial whether the flowers be wild or cultivated, 

 but as the latter are always to be had a few common 

 kinds may be mentioned as suitable: Sweet -pea {Lor 

 thyrus), Evening Primrose {(Enothera hiennis), "Willow- 

 herb (Epilohium), Fuchsia, Hollyhock {Althcea rosea), 

 Mallow {MaVoa crispa), Onion {Allium), Tulip, Tiger- 

 lily, Japanese Lily, Hyacinth, Gloxinia, Poppy {Papa- 

 ver), Pansy {Viola tricolor), or Chicory {Cichorium inty- 

 hus). The anthers of the flowers should be examined, 

 with a hand-lens if necessary, to see if they have 

 opened. If so, the pollen is in proper condition for 

 study, and will usually appear as a yellow, white, or 

 brown powder. 



In the examination may be used iodine, Schulze's 

 solution, potash, acetic acid carmine, and sugar. 



Method of Examination. — With the point of a needle 

 remove a little of the pollen to a slide, and examine first 

 in the dry state — i. e., without the drop of water and the 

 cover-glass. Afterwards prepare the pollen in the drop 

 of water in the usual way. Note particularly the differ- 

 ence in the appearance of the same kind of pollen ex- 

 amined in each of these ways. 



MOEPHOLOGT 



a. General Structure. — Do you find that the individual 

 pollen grains are visible to the unaided eye ? Do 

 you find any variety of shape, size, color, and 

 structure? Do you find that the color of the 

 individual grain is the same as that of a mass 

 of the same grains? "What do you find in the 

 way of markings, grooves, wing-like expansions, 

 points, etc., on the wall of the grains ? Can you 

 4 



