28 The Ottawa Naturalist. [May- 



willows and poplars provide good examples of fluffy seeds, but 

 though the air on some occasions -seems almost choked with 

 little pieces of fluff all of which contain one or more seeds it 

 will be observed that a very small percentage indeed alight on a 

 suitable place for the growth of the seedlings, and that a still smaller 

 percentage of these latter ever attain the size of their parents. 

 Yet who can find a moist place in nature, where the conditions 

 are favourable, that does not contain willows? Showing that 

 the object for which these countless millions of seeds went forth 

 has been accomplished. 



The milk- weeds, willow-herbs, bull-rushes and many 

 anemones are examples of this class of seeds. While ashes, 

 maples, conifers and docks are examples of the winged kinds. 

 There are some interesting details in this latter class for the 

 student to work out, which may be discovered by throwing up 

 into the air a few of the seeds on a moderately windy day. 



II. Seeds That are Scattered by 'Tumbling' Plants. 



This is a class of plants that depends upon the wind for the 

 locomotive power to take their seeds about the country. The 

 best known examples are commonly known as 'tumble weeds.' 

 These plants usually grow in the shape of a ball with their 

 branches rather tightly packed together. As soon as their seeds 

 are ripe they rot or break off close to the ground, and with the 

 first strong wind are sent rolling over the country, scattering 

 their seeds as they go. In the West where there are large plains 

 it is a common and interesting sight to see thousands of these 

 plants sweeping over the prairie, looking in the distance like 

 huge herds of cattle or sheep. In such places the country for 

 miles is sown with the seeds of these plants, especially Amar- 

 antus Alhus, Persian thistle, tumbling mustard, Cydoloma, etc. 

 Several grasses are also examples of this class, and many others 

 will occur to the reader. 



III. Seeds that are Scattered by the Wind. 



We now come to a class of plants which though dependent 

 on the wind to a large extent for their spread, yet have neither 

 downy nor winged seeds nor the power of tumbling. These are 

 plants that have the seed-capsules pointing upwards and which 

 open at the top. Many of these are so constructed that a strong 

 wind is required to shake the seeds out ; they are then not only- 

 scattered by the swing of the plant, but are caught up by the 

 wind as they are thrown out and are borne some distance away. 



