THE MYRTLE TRIBE, 51 



there is not a single species which possesses any useful 

 property worth mentioning. Remember, that num- 

 ber four, throughout all the parts of the flower, is its 

 character ; and you will be in no danger of either 

 forgetting it, or mistaking it. 



I have already said that other orders have, occa- 

 sionally, four parts of the calyx, or corolla, or of some 

 other class of org-ans, and vet do not belong to the 

 Evening Primrose tribe. I will give you an instance 

 of this. 



You know what a Myrtle is. Take a sprig of that 

 beautiful, but delicate evergreen, for your next sub- 

 ject. It has hard shining deep-green leaves, which 

 do not drop off when winter comes ; but seem as if 

 they were intended to make us forget that winter has 

 power over vegetation ; the stand opposite each other, 

 and if you bruise them, emit a fragrant aromatic 

 odour. If vou hold them against the lig-ht, vou will 

 see them look as if pierced with holes, closed up by 

 a green transparent substance ; they are not, how- 

 ever, pierced : but the appearance is owing to their 

 containing a vast number of little transparent cells, 

 in which the aromatic matter, to which thev owe 

 their fragrance, is laid up (Plate III, 1. jig. 10.). 



The flowers have a calyx of five divisions ; there 

 are five petals of a dazzling white ; and from the 

 sides of the calyx, there arises, in a ring, a very con- 

 siderable number of slender white filaments, tipped 

 by little roundish anthers {fig» 2.). 



The ovary, which is inferior, contains three cells, 

 and a good many ovules ; from its flat top springs 



E 2 



