EXTERNAL COXFIGURATION OF PLANTS. 193 



more ungainly stalk than the daffodil. Its thick- 

 ness, in proportion to the flower it bears, is much 

 greater than we should expect. By way of contrast 

 we may compare the slender elegant stem of the 

 Anemone or Chrysantheinum. No doubt the daffodil 

 stem is weak and succulent, but part of its thick- 

 ness may be due to its compressed form. We often 

 find mints and Carices growing together in marshes, 

 the tall stems of the Carex affording shelter to the 

 shorter mints. In these circumstances it is difficult 

 to resist the conclusion that the triangular stem of 

 Carex possesses some advantage over the square 

 stem of the mint. In the case of the nettle, if there 

 is any disadvantage attending the square stem, this 

 is abundantly compensated for by the strength of 

 its fibres. The wiry stems and small leaves of the 

 purging-flax are in keeping with its windy habitat. 

 Our heaths are also noteworthy on account of their 

 strong wiry stems and small leaves. Thalictrum, 

 from the consistency of its stems and the divided 

 character of its foliage, is well fitted for growing in 

 exposed places. The common Planfago lanceolafa is 

 especially deserving of mention. Its stiff fluted stem, 

 remarkable for its beautiful spiral vessels, is exceed- 

 ingly well suited to the open wind-swept pastures 

 where it grows. It attains a much greater height 

 than the allied P. major, which is not so well 

 adapted to the wind. 



No one can fail to remark that plants such as 

 orchids and hyacinths, with succulent herbaceous 

 stems, affect secluded and sheltered situations. In 

 autumn the grasses undergo a remarkable change, 

 losing their succulence, and assuming a dry and 

 wiry character. This desiccation is partly due, no 

 doubt, to the wind, but it also adds to their 

 elasticity. The hollow cylindrical stems of grasses 

 are said to have suggested to Stephenson the design 

 of the Britannia Tubular Bridge. A hollow cylinder 

 is very much stronger than a solid column of equal 

 weight. The wheat-stalk is thus constructed in 



