234 GENERAL BOTANY 



2. Pollen then is required to fertilize the ovules 

 Now it is a curious fact, which we cannot exactly 

 explain, though it has been proved in many cases, that 

 seeds formed by ovules fertilized with pollen from 

 the same flower, do not develop into such fine and 

 healthy plants, as do those fertilized by pollen from 

 a different plant of the same species. So that the 

 carrying of pollen from flower to flower is good for 

 the seed produced. 



In nature, pollen is taken from one flower to an- 

 other to a certain extent by wind, but in most cases 

 by small animals, especially flying insects, which are 

 attracted by the bright colour and the sweet scent of 

 the flowers, and come to suck the honey so often 

 found at the base of the petals, or to eat or carry away 

 the pollen. Bees, for instance, carry away and store in 

 their nests for future consumption, large quantities of 

 pollen, while Butterflies and Moths suck the sweet 

 liquid which is produced at the bottom of most 

 flowers. In doing this they inadvertently carry away 

 pollen grains on their legs, head, wings or other parts 

 of the body, and leave them on the sticky stigma 

 of some other flower. This explains what was said 

 in chapter xx, section 12, that pollen grains of small 

 inconspicuous flowers are usually smooth, those of 

 large or sweetly scented flowers, spiny or sticky. 

 Spiny or sticky grains would adhere to the legs and 

 bodies of insects much better than would smooth 

 grains, and, as a rule, insects visit only gaily coloured 

 or scented flowers. 



By patient observation and experiment, it has been 

 found that in any flower almost every detail of shape 



