THE FERTILIZATION OF ORCHIDS. 



Continued from page 18. 



Now let us see how the same work is done for orchids. 

 If we examine the fertilizing apparatus of one of our com- 

 mon orchids, — Orchis pyramidalis will serve our purpose, and 

 we shall very easily find it — we shall at once see how utterly 

 unlike it is to the inside of a lily, or of any other flower we 

 can call to mind. Let us cut away all the petals and sepals 

 of the flower, except the lower petal. This petal, which in 

 the orchids developes into a host of forms of every size and 

 colour, and is called the labellum., has very frequently a long 

 tube at the back part of it, the nectary, which from its surface 

 secretes the nectar — the drink of the gods in the days of 

 old, but now reserved for the insects. Looking at our flower 

 from the front we see the dark opening to the nectary under, 

 and hidden by a small roundish projection, whose use we 

 shall learn directly. The anther, above this projection, is 

 single, and, instead of the pollen being sprinkled all over 

 its surface, it has deposited within its substance two club- 

 shaped masses, consisting of little lumps of pollen-dust, held 

 together by a network of fine threads. The surface of the 

 upper part of the inside of the nectary, just under the 

 projection I have mentioned, is called the stigmatic surface^ 

 and v/hen the pollen is ripe, this stigmatic surface becomes 

 very sticky, and is prepared to fulfil the same function as the 

 stigma of ordinary plants, if only the pollen can get to 

 it — a thing absolutely impossible so far as we have seen. 



The pollen-chihs have stalks which run down through the 

 side of a small box — the projection I spoke of — and are 

 attached to a disc of membrane in it, on the under side of 

 which is some very adhesive gum, constantly kept moist and 

 fit for use, when once the flower is mature, by a liquid almost 

 like water, with which the box is filled. When all this is 

 quite ripe this box cracks across the front, and remains in 

 position, suspended by its lid, ready to open downwards on 

 the application of the slightest force. On the bright colored 



