MICROSCOPIC OBJECTS. 22 



Fig. 43. Pollen from Flower of Strawberry-tree (Arbutus 

 unedo) , x 200. 



Many pollens have a remarkably fine and beautiful appear- 

 ance when viewed under the high powers of the microscope ; 

 by their structure, many Natural Orders of plants, and also 

 the different genera, may be distinguished from each other ; 

 but I doubt whether the species of one genus can always be 

 distinguished from those of another. Pollens have been 

 comparatively little studied, and in this field alone much 

 work may yet be done. 



This pollen, being rather opaque, shows best when mounted 

 in the essential oil of lemon, or any other essential oil. 



Fig. 44. Stamens and Pistil of Dead Nettle (Lamium 

 album), x20. 



Stamens, as it is well known, deposit the pollen from their 

 anthers upon the stigma of the pistil of flowers, which is 

 depicted in this drawing. The pollen then throws out a tube, 

 which enters into the conduc ting-tissue of the pistil, and 

 passes on until it reaches an ovule or undeveloped seed, 

 which it then fertilizes. To investigate this fact, it is neces- 

 sary to cut a matured pistil from a partially withered flower, 

 subject it to moderate pressure, and mount it in fluid or 

 balsam. The stamens and the pistil of the Dead Nettle are 

 best when mounted in a dry opaque cell ; or they may be 

 mounted in balsam, and viewed under the parabolic reflector. 



