SNOWDROPS. 
29 
able and rough weather, and provides excellent protection from wet 
for the pollen. The anthers do not dehisce — that is, split open— to 
discharge the pollen, but are formed like sacks, with a small opening 
at the mouth, and each one has a slender and outward-curved 
appendage. If touched by an insect visitor the anthers would be 
shaken and the pollen scattered through the open end. The pollen 
is remarkably light and dusty for a bulbous plant, and may even be 
carried by the wind on dry days ; but the design of hanging anthers 
with openings only at the lower end, and trigger-like appendages, 
points so clearly to preparation for insect agency in the dispersal 
of pollen that we may conclude the flowers are mostly fertilized by 
bees. These cling to the inner segments and insert their heads 
and thorax in search of honey, and are freely dusted with pollen while 
so doing, when the Snowdrop flower is fresh and expanded. It is 
easy to shake the anthers by touching the triggers with a pencil 
point and to see a cloud of pollen fall out. 
Thus the pollination of the Snowdrop greatly resembles that of 
the widely different family of Heaths, in which we also find bell- 
shaped flowers with hanging anthers opening by pores and armed 
with triggers. 
A very interesting problem is offered by the shape and 
colouring of the inner segments. As all know, they are generally 
shorter by one-third than the three outer ones, with a two-lobed 
instead of a pointed tip (apex), or, to express it in another way, they 
seem to have a piece cut out of the centre to form a notch (sinus). 
On their outer surface there is generally a patch of green colouring 
following the outline of this notch, but which is in some forms reduced 
to two separate spots on the lobes only. We can find a clue to 
the evolution of this very peculiar formation by comparing Snowdrops 
with their near relations the Snowflakes. In these the six segments 
of the flower are equal in size and similar in shape. Each ends in a 
distinct lobe or claw with a green spot just above the narrowing 
and folding that form that claw. If we imagine a further growth of 
the three outer segments and the elimination of this little terminal 
fold, we should get exactly the form of a Snowdrop's outer segment. 
The green spot has disappeared, either from the expansion of 
tissues to form the extra size, or, as I think more likely, because it is 
no longer useful to the flower in guiding insects to the honey — in fact, 
it would be misleading in a widely expanded flower. On the other 
hand, the green marking is in all wild Snowdrops of normal construction 
intensified and specialized in the inner segments, and just round the 
most convenient place — that is, the sinus or notch — for the insect 
to insert its tongue. 
The arrest of growth of the central claw of the inner segments, 
and the elongation of the sides into the two lobes, explain their 
shape, and such a development is just that required to extend 
the rounded green spot of a Leucoium into the horseshoe-shaped 
mark of a Galanthus. 
