36 
potatoes, if placed for a fortnight in a cold chamber 
slightly above freezing point will readily develop when 
planted. A similar treatment is advantageous for 
rhubarb plants which are to be forced. Lift them out of 
the ground and let them dry and be exposed to light 
autumn frosts and they will then respond more readily 
to methods of forcing. This practice of thoroughly cool- 
ing plants which are to be forced is now regularly used 
in the case of bulbs, retarded Lily of the Valley crowns, 
Lilacs, Spirzeas, etc. Abroad, other methods have come 
into vogue with the same object in view. It has been 
found that the immersion of the branches of plants for ten 
to twelve hours in a hot-water bath of from 85 deg. to 
100 deg. Farenheit, has a remarkable effect in accelerating 
the unfolding of winter buds. The roots should not be 
so treated. It is therefore best to invert the plants and 
allow the stem and branches to hang down into the hot 
water. The effect of the latter is quite local; so that 
when partially immersed only those buds which have been 
under water are affected. Six weeks after this treatment 
lilacs will be in full bloom, if subsequently grown in the 
usual way. Professor Johannsen, of Copenhagen, has dis- 
covered that exposure of plants to ether vapour for twenty- 
four to forty-eight hours has a similar accelerating effect. 
Both methods are largely used on the continent. 
Let us now consider the structure of flowers and the 
function of thei various parts. So manifold is the 
appearance of flowers that it might seem at first difficult 
in a short space to make any general statement on their 
structure; yet as regards the essential organs of reproduc- 
tion we find considerable agreement. It is more par- 
ticularly in the structure of the brightly coloured petals 
that we find great variety, and largely owing to the 
adaptation of the flowers to the visits of insects. The 
colour and scent is developed to direct them to the honey 
which the flowers provide, and special honey guides, spots 
in the Rhododendrons and lines in Pansies and Violas, 
as well as differences in colour, guide them to the nectaries. 
In making their way to these the insects come in contact 
with the delicate stamens of the flower and the pollen 
contained in the pollen sacs at the tip of the stamen 
becomes dusted on to the insect. When it visits the next 
flower, some of this pollen will be dusted off on the stigma 
at the top of the immature seed vessel, and thus the insect 
