410 THE FERTILISATION OF FLOWERS. [PART III. 
stamens ; it is protected from rain by the inverted position of the 
flower. The anthers meet to forma cone; each dehisces on its inner 
surface, slowly from apex to base, letting the smooth pulverulent 
pollen run into the apex of the cone. The style with still imma- 
ture stigmas is inclosed within the cone of anthers. An insect, to 
reach the honey,must hang suspended below the flower, and thrust its 
proboscis between two stamens ; two anthers are thus slightly dis- 
placed, the point of the cone opens, and a little pollen falls out. 
i) 
Fie. 186.—Borago officinalis, L. 
1.—Flower, from below ; the stamens have been cut away. 
2.—A stamen in its natural position, viewed from the side. 
a, pouch in the corolla; b, cut end of stamen; c, ovary; d, fleshily thickened filament; e, pro- 
cess of ditto; f, orifice of the anther. 
The pollen in each anther ripens very gradually from the apex 
towards the base, and hence the little shower of pollen may be 
emitted repeatedly. The style only grows out beyond the cone 
of anthers and develops its stigma, after the anthers have been 
emptied of their pollen. Even after repeated insect-visits a per- 
manent displacement of the anthers cannot take place, for the 
short, broad form and fleshy nature of the filaments (d, 2), their 
stiff external appendages (ec, 2),! and the invaginated processes of 
the corolla that surround the base of the anther-cone, insure the 
return of each anther to its place after every disturbance. I have 
neglected to observe whether finally, in absence of insects, 
self-fertilisation may take place. 
1 Sprengel thought that these appendnay were for the purpose of sheltering the 
honey, but the inverted position of the flower renders this unnecessary. Delpino 
(No. 178, pp. 172-174) takes the view that I have adopted. 
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