150 LETTER XI. 



spread in all directions, and are admirably contrived 

 to catch the grains of pollen floating in the air. 



The fruit is an oval shining blackish lenticular grain 

 {fig. 8.), which contains a single seed, with an in" 

 verted embryo lying in the midst of fleshy albumen 



Such is essentially the manner in which all the 

 remainder of the Nettle tribe is organized. Pistils 

 and stamens in diffei'ent Jlowers, leaves covered with 

 rough or stinging hairs, elastic stamens, and lenticular 

 grains, are common to them all. 



Nettles, which are so remarkable for the intolerable 

 pain, and even the sometimes highly dangerous ef- 

 fects caused by their stinging hairs, differ from Pel- 

 litory chiefly in their pistil-bearing flowers having a 

 calyx of two sepals. 



Hops have not only a twining stem, and their 

 pistil-bearing flowers collected in leafy heads, but 

 are also known by having five stamens in each sterile 

 flower, and the pistils and stamens on different plants. 

 Finally, Hemp, which also belongs to the Nettle 

 tribe, has the calyx of the pistil-bearing flow^ers slit 

 on one side, two unequal styles, and five stamens in 

 the sterile flowers. The peculiar tenacity of the stems 

 of Hemp is not uncommon in other plants of the same 

 natural order, and may even be considered charac- 

 teristic of it. 



Considering the many important purposes to 

 which the Hemp is applied, and the prodigious 

 strength that it possesses when twisted into ropes, 

 vou will probably be curious to know something of 



