267 
THE PRINCIPLES OP BOTANY. 
By Professor James Buckman, P.L.S., F.O.S., &c. &c. 
[Continued from p. 154.) 
Before considering the subject of the metamorphoses of 
the parts of flowers of plants it will be well to enter into a 
more minute description of the structure and action of the 
pollen. 
The fertilising powderV or dust/’ as it is called^ is most 
interesting and varied in the form and size of its grains. It 
may be briefly described as a separable cell^ and is^ indeed_, 
the true seminal matter of a plant. At the same time we 
must not quite conclude the pollen grains to be separable cells, 
as in their turn they are often formed of a congeries of cells 
which are highly complicated in structure. 
If we examine the pollen of any of the lily tribe of plants 
we shall find it somewhat large in size, and we may, therefore, 
the better make out its structure. 
In the accompanying woodcut we have a representation of 
the pollen grains of the tiger lily, as seen under a Powell 
Eig. 9. —a and h. Pollen of the Tiger Lily. a. Showing the exsertion 
of the pollen tubes, b. Burst and discharging its fovilla—4 iii- 
objective, c. Pollen of Eorget-me-not, I in. objective. 
and Lealand’s 4th inch objective (fig. 9, «, h), which may 
