154 
POPULAK SCIENCE EEYIEW. 
on a slide under a covering glass, and viewing with one- 
quarter or higher powers. The mode of growth of the 
pollen buds will then be seen, and it will be found that the 
cells below the epidermis often present curious and beautiful 
appearances of spiral or other fibres. The Siberian Squill, 
common in gardens {Scilla Sibirica), and as a pot plant, shows 
the spiral fibres something like those in the leaves of Sphag- 
num exceedingly well. The “ Micrographic Dictionary ” 
gives, amongst others. Narcissus poeticus^ Populus alba, and 
Datura Stramonium,, as having spiral fibres ; Iris florentina, 
Hyacinthus orientalis, and Convallaria, as having annular 
fibres ; Tritillaria imperialis (internal face), and Viola odorata 
as having reticulated fibres ; Nuphar lutea, Bryonia dioica, 
Primula sinensis, and Lupinus, as having arched fibres, on 
three sides of the cells, the fourth free. Trumpet Lilies, Cal- 
ceolarias, and Larkspurs, should also be examined, as their 
fibres stand upright. An investigation of a dozen or two of 
flowers easily found in a garden or conservatory would well 
repay the trouble. 
Botanists regard all the outgrowths from the stems of plants 
as leaves of some kind, however they may be modified in form or 
colour. What are commonly known as “leaves” of course 
retain that appellation in scientific works ; but sepals, petals, 
anthers, &c., are all morphologically considered as modified 
leaves. At first this sort of philosophy appears exceedingly 
far-fetched and difficult; but there are several easy modes of 
getting a sufficient insight into the matter to show that it is true 
in certain groups of cases ; and when the student has got thus 
far, he need not be in a hurry to doubt that with greater know- 
ledge he would find it true in others. In regarding various parts 
on modified leaves the notion must be avoided that a true leaf 
is made first, and the particular parts made out of it afterwards 
by modification. This would be quite wrong. What is con- 
sidered is, that the various parts begin as leaves begin, and 
that their growth is modified as it goes on, the cells of which 
they are composed arranging themselves in given directions and 
quantities, according to the nature of the patterns ultimately 
required. Nothing can appear more different than the ordinary 
leaf of a plant and its stamens with their filaments. But in But- 
tercups, Bachelor’s Buttons, &c., a quantity of stamens pass into 
the condition of flower-leaves or petals; and if a wild single Eose 
is compared with a full-leaved garden variety, it will be found 
that the “ doubling” has consisted in the development of the 
anthers and filaments into floral leaves. The elegant double 
Cherry that flowers in Spring is another illustration of stamens 
taking the petal form. 
Minor modifications of the filament are also common, and 
