14 SOUTH AFRICAN FLOWERING PLANTS, 



The first, or a healthy life, follows all three methods 

 equally well, provided the outside conditions be all that 

 are required. 



As to the quantity of seed set, as the chance of not 

 being pollinated by insects or the wind is always 

 present, but never so in the last, the probability of 

 their being the best off would seem to lie with self- 

 fertilized flowers. When we look to see what happens 

 in Nature, we find such to be by far the most prolific, 

 Shepherd's-purse and Chickweed, imported from Europe, 

 are examples. If they be allowed to grow and seed in 

 a garden, they will soon smother everything in it. 



Crossing, whether by insects, or if it be done arti- 

 ficially, as practised by florists, has the effect of 

 stimulating the plant to produce larger and more 

 brightly coloured flowers. Consequently, it is much 

 practised in gardens, but it is often done at the expense 

 of fertility ; for it is found that after some years the 

 amount of good seed, which will reproduce the best 

 flowers, diminishes, so that the experimenter gets to 

 the end of his tether, and he may even lose his whole 

 stock altogether from the seed entirely failing. 



I will now describe more in detail each of these 

 three methods of pollination. There is a fourth, namely, 

 when the pollen is conveyed by water, as of the sea- 

 grass, a submarine flowering plant, but it is very rare 

 for flowers to be fertilized in this way. 



