and are only visited by bees and humble-bees. The common 

 humble-bee has a long enough tongue to reach to the tip 

 of the spur and is the chief agent in the fertilisation of the 

 plant. The orange-yellow spot at the only opening to the 

 flower is equivalent to a notice " this way to the honey." 

 Should no insect visit a flower self-fertilisation will nevertheless 

 occur and seeds will be produced all the same. A variety of 

 this plant, with flowers of a uniform red-violet colour and with- 

 out any orange-yellow spot, grows on primary granitic rock. 

 A second and much rarer type has pure yellow blossoms. 



The plant is sure to be easily recognised. The prostrate 

 stem, narrow leaves, and entirely closed up flowers that grow 

 together in bunches are some of the more characteristic 

 features. 



^7 



