264 THE STORY OF PLANT LIFE 



burst irregularly. In the female flowers the ovary 

 is one-celled, oblong. There is a terminal style, 

 which is awl-like, and persists. The stigma, which is 

 one-sided, is covered with papillae. The single ovule 

 is pendulous from the top of the cell, and ortho- 

 tropous. The fruit, which is seldom produced, is 

 hard and leathery, and does not open. It is tubercled 

 below, with wings or spurs. The seed is pendulous. 

 There is a membranous testa, and the hilum is 

 thickened. The seeds are albuminous, though 

 Hooker says they are not. The cotyledon is two-fid, 

 ovoid, thick, the plumule large, many-leaved, and 

 the radicle is very short. 



The flowers open under water and are pollinated 

 by water agency. The stigmas are sticky, and the 

 pollen, containing a tannin-like substance of a pro- 

 tective nature, sticks to them. 



The fruits are dispersed by water. 



There are no properties of economic value. 



Horn WORT {Cerafophyllum demersum). 



Even the well-informed botanist in the majority 

 of cases has little or no acquaintance with the 

 Hornwort, for like the aquatic-wading birds, the 

 plant, if one may use the expression, skulks under 

 water, and is seldom visible from the bank of a river 

 or pond, being quite submerged and usually in- 

 accessible. Consequently it is not a matter for 

 surprise that the non-botanist has frequently never 



