182 TALKS AFIELD. 



form and its habit of floating a little be- 

 neath the surface, and the other (enlarged 

 at B^ flattened above and floating on the 

 surface. Although these plants are so very 

 small, they often occur in immense quanti- 

 ties. I have seen them piled up five inches 

 deep on the borders of a wind-swept pond. 

 At C in Fig. 91 is shown a plant in flower, 

 the front half of the plant being cut away. 

 The little plant is monoecious ; the stamen, s, 

 comprises one flower and the globular pistil, 

 /?, the other. They are both sunk nearly to 

 their tops in the frond. These plants prob- 

 ably do not blossom in this northern climate. 

 They propagate after the manner of the 

 lemnas by means of offshoots. In C is 

 shown a young frond, 5, springing from the 

 parent. 



Some forty years ago a Frenchman, Mons. 

 H. Weddell, was traveling on the Paraguay 

 River, in South America, and having shot a 

 rare water-bird, he observed that its feathers 

 were covered with peculiar green grains. 

 Upon turning to the pond where the bird 

 had been wading he observed that it also 

 was covered with the little grains. Mons. 

 Weddell was a botanist, and he soon found 

 that the little plant was in full bloom. He 



