HOW FLOWEBS CLUB TOGETHER. 149 



mentally tlie very different way in which the 

 flowers are arranged in the lily-of-the-valley, the 

 foxglove, the Solomon's seal, the heath, the 

 scabious, the cowslip, the sweet-william, the 

 forget-me-not, in order to see what variety 

 natural selection has produced in all these 

 matters. Two instances must serve to illustrate 

 their mode of action. The foxglove grows in 

 hedgerows and thickets, and turns its one-sided 

 spike towards the sun and the open ; its flowers 

 open regularly from below upward, and are 

 fertilised by bees, who enter the blossoms, and 

 whose body is beautifully adapted to come in 

 contact, first with the stamens, and later with 

 the stigma. (Examine this familiar flower for 

 yourself in the proper season.) In the forget- 

 me-not, on the other hand, the unopened flowers 

 are coiled up like a scorpion's tail ; but as each 

 one opens, the stem below it lengthens and 

 unrolls, so that at each moment the two or 

 three flowers just ready for fertilisation are 

 displayed conspicuously at the top of the 

 apparent cluster. 



There are two forms of cluster, however, so 

 specially important that I cannot pass them 

 over here without some words of explanation. 

 These are the umbel and the head, both of 

 frequent occurrence. An umbel is a cluster in 

 which the flowers, standing on separate stalks, 

 reach at last the same level, so as to form a 

 flat-topped mass, like the surface of a table. 

 An immense family of plants has very small 

 flowers arranged in such an order ; they are 

 known as umbellateS;, and they include hemlock. 



