2 2 PLANT LIFE. 



some other chemical cause, it is clear, as anyone can see 

 by an hour or two's observation in a garden, that the 

 red would at once catch the insect's eye ; and that red 

 flowers would be most frequently visited, and hence 

 leave most seed. 



The way in which flowers are placed on the stem 

 brings out, very clearly, the fact that an attempt is often 

 made to save the insect as much time and trouble 

 as possible. The diagram shows some of the common 

 arrangements of flowers on the inflorescence, starting 

 with the Tulip, which is perhaps the simplest of all. 



From these two sets of inflorescence, it is seen that 

 in three of the largest orders, Compositae, Umbelliferae, 

 and Labiatae, the flowers are brought as close to one 

 another as possible ; so that the insect will lose no 

 time in going from one to another. Even in cases 

 in which this is not obvious at first sight, as in the 

 Foxglove and many Cruciferae, the flowers are really 

 very close, and very little time is wasted by the 

 insect in going from one to another. In the Forget-me- 

 not, the protection of the young flowers has influenced 

 the arrangement, and they are carefully hidden under- 

 neath the stalk until they are ready to take their place 

 exactly in the way of a passing insect. The loose 

 drooping arrangement of the Oat and many panicles is 

 no exception. It is the wind, not insects, which carry 

 the pollen, and the suitability of a loose waving in- 

 florescence for such flowers is quite clear. 



(vii.) In addition to insects, other animals are 

 utilised in the transport of pollen. Thus the Golden 

 Saxifrage, in which there are small, inconspicuous, 

 greenish-yellow flowers, is said to be visited by snails or 

 slugs, which crawl over the flat surface formed by the 

 little group of flowers at the top. 



